Talk:Globally Unique Identifier

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This article may be too technical for a general audience. Please help improve this article by providing more context and better explanations of technical details to make it more accessible, without removing technical details.

Is anyone familiar with the term "ProgID" to mean a text alias for a CLSID? It is used in developing COM objects for ArcGIS. If this term is in common use, we ought to add it.

I'm changing "mathematically guaranteed" to "statistically guaranteed". Statistically, a 1 in 2^128 chance may seem infinitesimal. Mathematically, it is no closer to infinitesimal than, say, 1 in 4. Admittedly, the phrasing here is a matter of style, or personal preference. (Oops, and it looks like I wasn't logged in when I did the edit. Sorry about that.)

--DavidConrad 03:45, 23 Jun 2005 (UTC)

ProgID is described quite well here: [1]

DRead 23:42, 24 October 2006 (UTC)

I beleive that the original (V1) algorithim contained several features to procedurally guarantee the uniqueness of a GUID, at least on this planet. Primary among these features was the use of a MAC address in the GUID, since a centralized authority is used to assign ranges of MAC addresses to equipment vendors. Pressure over the perceived privacy issues related to embedding a MAC address in a GUID lead Microsoft to change the default algorithim used for GUID generation to one which uses a random number in the last segment. This weakens the level of gaurantee of uniqueness to a purly statistical one. However, at the same time, Microsoft introduced an extended API allowing callers to generate GUIDs using the original algoritihm.

Burt Harris 21:34, 14 January 2006 (UTC)

Contents 1 Doubt that this article has a NPOV. Incorrect content! Pls. review! 2 Response to claim of non-neutral point of view 3 how about a disambiguation article? 4 This is pretty poor. 5 Not really 2128 unique numbers 6 List of common GUID's? 6.1 CLIDs 7 This is a terrible idea.. 8 Text Encoding 9 Case Sensitivity

[edit] Doubt that this article has a NPOV. Incorrect content! Pls. review!

Sorry... but this article is just a piece of... RNGs or better said PRNGs do not produce 128bit numbers by default. The numbers produced depend directly on a seeded value. If the seed value is the same a PRNG will produce the same sequence of numbers. If the seed value is not of 128bit by default or ... then there will be some problems.

Just a subset of all possible GUIDs will ever be produced. There will be a HIGH rate of collisions. The probability of a collision is much higher than assumed in this article with the described procedure to produce the GUIDs.

The term GUID is not just used in the Microsoft world. Microsoft is not the standardization commitee for the GUIDs.

GUIDs are not 128Bit by default. Doing a simple look up in Google I easily found a lot of websites refering to GUID of length 32bit, 16bit, 160bit, too. If this article intends to describe Microsoft GUIDs (if some clean defacto standard (not de jure)like that exists) then we should do a clean disambiguation.

It's a misleading and incorrect article stressing the Microsoft Cooperation in that amount that it might be more advertisement than explanation what a GUID really is and what might be an optimal design for a GUID.

Please review that article and make sure the NPOV is given!

--212.114.211.8 09:18, 10 August 2006 (UTC)

I believe that perhaps this article should be merged into Universally Unique Identifier. The term GUID (versus UUID) was from the best I could ever discover a Microsoft-invented term. They had taken several basic ideas from already-existing OSF DCE (including the UUID) and in typical fashion given it a new name when they created their own re-implementation of it. Until the last few years the term GUID was almost exclusively in reference to Microsoft usage, and UUID was the term used pretty much elsewere. However, other than perhaps specific generation algorithms and terminology, a UUID and GUID are basically the same thing and the terms are now used (or misused) almost interchangably now, and should probably be discussed within the same article. In fact the UUID is really sort of a super-set of the GUID. The earliest mention of both together is found in the Leach draft from 1998 (although UUIDs had existed many years prior)[2] It may well be that the terms have recently seen some application with a more generic meaning for all kinds of unique identifers, but in the "standardized" and historical sense they are both 128-bit quantities with a definite (although variant) construction. --Dmeranda 21:09, 10 August 2006 (UTC)

--d-axel 08:08, 26 August 2006 (UTC)-- I am not an expert but even so I could easily see through the possible bias of the original article here. I enjoyed and learned a lot. Beginning a comment with a very derogative expression is not helping anybody, so I would guess that User:212.114.211.8 has had many annoying situations where his expertise was neither heard nor acknowledged. But please, number 8, do moderate yourself before moderating others. You sound like a true expert! :-)

A non-biased (Neutral Point Of View) version should emphasize that PXE boot is influenced by the fight for market shares and possibly for control over the consumer electronics market.

There is a strong focus on policies which can use ID of machines for control due to license and copyright earnings. This is natural and should not be viewed as a non-neutral point of view.

It should not take much space in the final article, though.

As an example of how licensing strategies influences other unrelated areas I would like to mention system deployment, unfortunately also an area for experts only: Deployment of an Operating system with 1 GB stuff need only take 3 minutes on an average 100 mbit network if there were no time-consuming license mechanisms involved. For the non-expert it might very well take half an hour and much more if no special tools are used. --d-axel 08:08, 26 August 2006 (UTC)

It seems that all editors generally agree on what should be done and what bias is here. I suggest to just be bold and go ahead, making whatever changes are needed to fix it. Or is there any controversy? CP/M ^comm |Wikipedia Neutrality Project| 01:37, 17 September 2006 (UTC)

[edit] Response to claim of non-neutral point of view

Wow, there's been a of discussion since I last looked. Thank for the input. I don't know how anyone can claim be an experit on GUIDs, any more than they can claim to be an expert in 2's compliment binary integers. They are both just data-types, and we only know about how we've used that data type in the past.

I think I can qualify as an expert on Microsoft's use of the GUID, but I'll leave that to the community to decide. I won't claim to have an entirely non-biased point of view, I think all of our POVs are biased to some degree or another by our past experiences. I've been doing development work for over 25 years. I used DCE RPC and provided training and consultation on COM development, both as in independent consultant and later as a Microsoft employee. You'll find me acknowledged as a contributor to the book Inside OLE 2 by by Kraig Brockschmidt (Microsoft Press, 1993) ISBN: 1556156189, and later in the 2nd edition o this book.

That said, I'll agree with most of the comments on this discussion page, save those of 212.114.211.8. His/her comments are offensive to me. I'm jsut trying their best to contribute some knowlege while remaining as neutral as possible. It is was my understanding that a discussion page, like this one, is a place where potentially biased thoughts were to be discussed, and I've tried not to let my POV bleed into the main article.

I agree 100% that GUID and UUID are, from a practical standpoint, interchangable terms. Merging the articles might make sense, but I'll note that I've encountered the term GUID more in a Microsoft-related context and UUID in broader context, but I certainly wouldn't ever claim that Microsoft invented the concept. Personally I think Globally Unique ID is a more accurate description than Universially Unique ID, the universe is a pretty big place (do we even know how big?), so GUID is my preferred term.

I don't fully understand the some points d-axel is raising. Its true that PXE boot can use a GUID/UUID as a machine identifier. This has something to do with the SMBIOS standard. My understanding is that the option to use GUID's for boot-time machine identification is simply to eliminate the ambiguity of using MAC addresses on machines with more than one network adapter. What puzzles me is that I'm totally unaware of how this is connected to a fight for market share. I'd be interested in learning more about this, though I agree it doesn't seem appropriate in an article about the data type. Perhaps it belongs in an article about PXE boot.

I don't know how disputes over NPOV are resolved here, but I want to contribute where I can. I'd be willing to tackle reorganizing the main topic if there's general agreement to it, but with discussion questioning my neutrality, is that appropriate?

--Burt Harris 19:16, 16 September 2006 (UTC)

It seems that problem is not neutrality of text, but just lack of information which makes it too Microsoft-centered. Please just forgive the IP user for some offensive comments, it can happen sometimes, let's just better look only at the arguments. Merging the articles could be considered as well - what are other editors' opinions? CP/M ^comm |Wikipedia Neutrality Project| 01:54, 17 September 2006 (UTC)

Thanks CP/M. That's a good way to look at it. I was recently referred to a great document, ITU Reccomendation X.667 which clarifies several issues, including saying clearly that GUID and UUID are effectively synonyms. Unless there are objections, I'll make an update to incoroporate this information, and merge the topics. --Burt Harris 20:43, 27 September 2006 (UTC)

I'm all for a merging of UUID and GUID. I also agree that the POV concerns really reduce to just a lack of information beyond the MS world; which merging the articles will help resolve. Although UUIDs came first, I suspect most of the world nowdays is more familiar with GUID, so I think merging UUID into GUID makes the most sense. There are perhaps some structural/organization edit work to be done too, but let's give the merge a shot first and then we can polish the resulting article after. I'd suggest that you go ahead and add the appropriate merge tags to the top of each article. [Oh, glad to meet you Burt, that OLE book is one of the few MS-related books I ever bought; I'm normally a Unix guy with a DCE background] --Dmeranda 17:00, 28 September 2006 (UTC)

Merging is not the correct approach. As an encyclopedia we should reflect the view of "a common ground" and not try to squeeze the world into our own look. As we see in this discussion, people differentiate between UUID and GUID, because of technical and social differences. GUID is more Microsoft centric and a word often used for the GUID datatype in ActiveX and MSSQL Databases, where it is clearly defined. GUID can be used independent of microsoft, but people who use it may be thankful to know the correlation. The term UUID is used in a similar, but it seems different context. Both articles should remain, but give information about these aspects so that the general public can learn from our insights. Leobard 13:52, 15 March 2007 (UTC)

-- ITU-T ASN.1 Project leader, 29 September 2006

The introduction of ITU-T Rec. X.667 | ISO/IEC 9834-8 "Generation and registration of Universally Unique Identifiers (UUIDs) and their use as ASN.1 Object Identifier components" that you can freely download from the ITU-T website and that is technically aligned with IETF RFC 4122 states:

"UUIDs are also known as Globally Unique Identifiers (GUIDs), but this term is not used in this Recommendation | International Standard. UUIDs were originally used in the Network Computing System (NCS) and later in the Open Software Foundation's Distributed Computing Environment (DCE). ISO/IEC 11578 contains a short definition of some (but not all) of the UUID formats specified in this Recommendation | International Standard. The specification in this Recommendation | International Standard is consistent with all these earlier specifications.]"

So this is also in favour of merging the GUID article into the UUID article.

I would not say that, this is only a reason to prefer one view (of the ITU) over the view of another community (microsoft-aware developers). The ITU quote given states that the term GUID is not used in the recommendation. As with any standard, it can only reflect the view of one particular person (the editor of the standard) and the agreement of many (the signers/authority behind the standard). We should refer to the UUID article from the GUID article, but not merge them. Leobard 13:59, 15 March 2007 (UTC)

BTW for those interested, a website is associated to the UUID International Standard.

[edit] how about a disambiguation article?

We have seen that GUIDs can be interpreted in the strict Microsoft-sense used in MSSQL and ActiveX/COM and that the term can also be used generally. We could disambiguate GUID (microsoft) and GUID (ITU). The wikipedia should reflect other sources as best as possible, if divergent sources exist out there, a disambiguation may reflect the discussion better than one GUID article that tries to squeeze all aspects in Leobard 13:59, 15 March 2007 (UTC)

[edit] This is pretty poor.

The definition of guid from guiddef.h is as shown below:

[...]

i.e. a concatenation of a 4-byte number, two 2-byte numbers and eight single bytes.

Except that this C code, where these sizes are only true on platforms where longs are 32-bit, shorts 16-bit, and chars 8-bit, none of which is guaranteed by the C standard at all.

This text notation follows from the data structure defined above.

Except it doesn't, because Data4 is split in two in the text notation, while it's a single item in the data structure.

Not impressive. I'd fix it myself, but the page is asking for an expert, and that I am not. 81.86.133.45 15:40, 25 March 2007 (UTC)

Fixed. The article was indeed rather lousy on this point. Shinobu 01:12, 27 June 2007 (UTC)

[edit] Not really 2¹²⁸ unique numbers

If, as the Globally Unique Identifier#Algorithm chapter says, GUID reserves parts of its layout for versioning, then there cannot be 2¹²⁸ unique numbers. --Abdull 14:39, 4 April 2007 (UTC)

Oh, and one more: who or what is the mentioned OSF? --Abdull 14:52, 4 April 2007 (UTC)

Both fixed. Shinobu 00:39, 27 June 2007 (UTC)

[edit] List of common GUID's?

Perhaps it would be nice to have a list of common GUID's in the article.

Like e.g.:

{00000000-0000-0000-C000-000000000046} IUnknown
{00020400-0000-0000-C000-000000000046} IDispatch
{00020401-0000-0000-C000-000000000046} ITypeInfo
{00020402-0000-0000-C000-000000000046} ITypeLib
{00020403-0000-0000-C000-000000000046} ITypeComp
{00020404-0000-0000-C000-000000000046} IEnumVARIANT
{00020405-0000-0000-C000-000000000046} ICreateTypeInfo
{00020406-0000-0000-C000-000000000046} ICreateTypeLib
{20D04FE0-3AEA-1069-A2D8-08002B30309D} My Computer
{21EC2020-3AEA-1069-A2DD-08002B30309D} Control Panel (Windows)

Information like this is currently a pain to find. (Disclaimer: I haven't checked these, I just searched the web. You can also find some GUID's in the registry and in the Windows header files.) Of course there would be the question of what to include and what not to include, but I'm sure we can figure something out.

It would also be nice if 00000000-0000-0000-C000-000000000046 linked to IUnknown, but I'm not sure what Wikipedia policy says about that, so I won't make these redirects (unless prompted to do so at least). Bye, Shinobu 00:56, 26 June 2007 (UTC)

On the face of it a GUID list/index seems like a good idea, with the caveat that the MS UUID spec could very will be completely different for Vista (MS not being big on backwards-compatibility and all). I'd advise sticking to only the very most common identifiers, otherwise that list will get unwieldy in a hurry. As for the redirect question... well, that begs a few additional questions. Could you create redirs for common GUID's, i.e., is it feasible? Sure: I've heard the refrain "redirects are cheap" parroted a few times by WP'ers. Should those redirs be created? I don't know. If "00000000-0000-0000-C000-000000000046" and the like are going to be common search terms, then absolutely. If not, then I could forsee complaints that a GUID/UUID is too trivial a thing to be creating a redir for (I suppose there's also an outside chance that an illegal number type copyright complaint could be lodged too). That's my two centidollars. Groupthink 22:27, 27 June 2007 (UTC)

All the GUID's in the Platform SDK (at least those that are part of the API) are necessarily public. It is likely that "illegal GUID's" exist, but I wasn't thinking about those. Note that some of the GUID's from the Platform SDK are used elsewhere on Wikipedia, and in WINE and ReactOS as well. Anyway, I could try to compile and categorize a list. If it's decided we want it, that is. Shinobu 09:15, 28 June 2007 (UTC)

I fear that "public" and "illegal" aren't necessarily mutually exclusive. If I were to post the entire Java class library, for instance, I don't think Sun would be too happy with me. Let me reiterate though that I think that's at best a secondary concern: the primary questions IMHO are utility and maintainability. Groupthink 13:04, 28 June 2007 (UTC)

In this case however, they are. Because they are part of the API of Windows and various other programs, even non-Microsoft software, programmers need to be able to include these GUID's in their programs whithout Microsoft then dictating the licensing terms. When you just interface the API, by default what you program yourself is your own intellectual property, in exactly the same way that Microsoft cannot forbid you to use the function name GetDIBits and in the same way as programming for GNU/Linux cannot legally force you to make your program available under the GPL. If Microsoft had wanted to fix its licensing terms upon us, it should have clearly stated those, as indeed it did with the Windows Media SDK. Instead, Microsoft chose not to do so and indeed emphasises the open and cross-platform nature of COM. Note also that these numbers are not secret decryption keys or something similar, but identifiers. IID 00000000-0000-0000-C000-000000000046 is a synonym for the IUnknown interface. Furthermore note that your example is a bad one in two ways. 1) You're actually talking about Sun's code here, not about the API. Your scenario is much more akin to making illegal copies of Windows. 2) Sun actually won't mind, since they're going open source and free software all the way with Java. Of course, IANAL, and even if I were, the Wikipedia servers are in Florida, a place with very strange and convoluted laws, or so I'm told. Shinobu 08:46, 4 July 2007 (UTC)

Let me re-reiterate that the primary concerns IMHO are utility and maintainability. As for the Sun example: I was talking about the API, not the code. The scenario I was worried about was, say for example, carbon-copying this page to Wikipedia and trying to hide behind "well it's open-source anyway" as an excuse. I still don't think you'd be absolved of licensing issues in that case. And let's remember that this is Microsoft we're talking about here. If they were to complain about a comprehensive list of GUID's, they might not have a leg to stand on, but they could conceivably make enough of a stink to cause problems. Groupthink 05:16, 5 July 2007 (UTC)

I disagree strongly with including a list like this. This is an encyclopedia article that is for discussing the facts of the topic with prose, not listing trivia. I'm sure some people might find this information useful, but an encyclopedia is not the place to go to for such highly specific and frankly largely uninteresting information. If it's hard to find on the web then it would be worth submitting somewhere more suitable, like a technical blog. Remy B 14:27, 2 September 2007 (UTC)

[edit] CLIDs

I've found the following list of CLIDs here. I don't think this is really trivia, but rather technical infomation about CLIDS/Windows.

{D20EA4E1-3957-11d2-A40B-0C5020524153} Administrative Tools 
{85BBD920-42A0-1069-A2E4-08002B30309D} Briefcase        
{21EC2020-3AEA-1069-A2DD-08002B30309D} Control Panel    
{D20EA4E1-3957-11d2-A40B-0C5020524152} Fonts
{FF393560-C2A7-11CF-BFF4-444553540000} History
{00020D75-0000-0000-C000-000000000046} Inbox
{00028B00-0000-0000-C000-000000000046} Microsoft Network
{20D04FE0-3AEA-1069-A2D8-08002B30309D} My Computer
{450D8FBA-AD25-11D0-98A8-0800361B1103} My Documents
{208D2C60-3AEA-1069-A2D7-08002B30309D} My Network Places
{7007ACC7-3202-11D1-AAD2-00805FC1270E} Network Connections
{2227A280-3AEA-1069-A2DE-08002B30309D} Printers and Faxes
{645FF040-5081-101B-9F08-00AA002F954E} Recycle Bin
{E211B736-43FD-11D1-9EFB-0000F8757FCD} Scanners and Cameras
{D6277990-4C6A-11CF-8D87-00AA0060F5BF} Scheduled Tasks
{7BD29E00-76C1-11CF-9DD0-00A0C9034933} Temporary Internet Files
{BDEADF00-C265-11D0-BCED-00A0C90AB50F} Web Folders 

Ideas? Fosnez 02:20, 14 September 2007 (UTC)

[edit] This is a terrible idea..

let me get this straight. Assuming dupe GUIDs causes a fatal error, and assuming the average computer generates and stores some 1000 GUIDs in the course of its lifetime... one in 530 nonillion computers will just randomly crash? No matter how astronomically improbable, this is clearly not the Right Way. --froth^t 15:16, 2 August 2007 (UTC)

Then what do you propose? In some circumstances it is necessary to be able to generate reasonably unique identifiers without the use of some kind of central authority. Or it may happen that the drawbacks of using such a central authority outweigh the chance of a GUID clash. GUID's solve this problem. If you have a problem that cannot be solved using GUID's, then don't use them. Talking about the Right Way like you do is meaningless - what is the right way depends on the problem you want to solve, and GUID's are pretty adequate at solving the problem they were designed to solve. In that sense, GUID's are the right way, but note that I refuse to use capitals here, since, as I said, the right way depends on the problem that needs to be solved. Shinobu 21:17, 24 August 2007 (UTC)

[edit] Text Encoding

Is 7QDBkvCA1+B9K/U0vrQx1A== actually the Base64 encoded value of {3F2504E0-4F89-11D3-9A0C-0305E82C3301} or is it just an example of the format...? —Preceding unsigned comment added by 206.170.173.254 (talk) 17:24, 6 November 2007 (UTC)

[edit] Case Sensitivity

Someone referenced this page to me. As part of their explanation, they rationalized that since the values were based on hexadecimal digits, they were case sensitive. I don't know how that connection was made from reading the text of this WIKI, but an explanation of the significance, if any, of case in the GUID would be helpful. Possibly along with a side note that hexadecimal values are not case sensitive.

Thanks, non_ame@yahoo.com

66.193.125.254 (talk) 16:46, 18 January 2008 (UTC)