I suspect we will have to discuss tags and their usage on a regular basis. Let us do so here; I propose one answer per instance and discussion in the comments.

Note that you can link to tags using a shortcode. For instance, [tag:context-free] becomes .

Please help with tag descriptions! These are the text that shows up when you hover over a tag (excerpt) and when you click on "info" in this popup (full version). For tags without description, you can propose one by clicking on "help us edit this wiki" in the popup; in general, the tag info page will show edit buttons.

If you suggest tag wiki entries, please keep in mind that excerpt should be short; it is shown in the boxes that pop up when hovering over a tag (on the main site). Have a look at the tag list; there are only three short lines for every tag. Therefore, the excerpts need to be snappy and descriptive. The community mods have rejected some of my suggestions on the grounds of length; I guess we should keep them at about 150 characters. You are very welcome to elaborate in the main text, though!

• Uh... Why would you have all these unrelated discussions in one thread? History shows this tends to fall apart once there are more than a few answers. Post new discussions, with specific titles, so folks can jump in on the ones they're interested in. Mar 15 '12 at 17:26

This question is currently tagged ,, and .

• Please suggest tag wiki excerpts for the tags you use so we know what they are supposed to me. In particular, I have not idea what "otp" is supposed to mean.
• It seems to me that is a synonym of . If not, please suggest tag wiki excerpts to clarify the difference.
• is incredibly vague; one could argue that computer science is about information. Maybe would be more appropriate, or is this used differently?

• crypto is not synonym of encryption but a very broad family that includes signature, authentication methods, pseudo-random generators, one-way functions, etc. Mar 14 '12 at 7:29
• otp, is actually "OTP" which stands for one-time-pad, one of the most famous and well known (and the only provably secure) encryption scheme Mar 14 '12 at 7:30
• information vs information-theory: I don't know. I saw earlier a tag data-compression that in my eyes should have been simply compression. I like brevity, but it is a matter of taste. Mar 14 '12 at 7:31
• compression and data-compression are synonyms (in CS), information and information-theory are not. Therefore I think the distinction is necessary. We can deal with unnecessarily long tags later by introducing tag synonyms, so we tag should as descriptively as possible now (imho).
– Raphael Mod
Mar 14 '12 at 7:35
• what will information mean? Mar 14 '12 at 7:36
• I don't think information should ever be used as a tag as it is an all-encompassing notion in CS. Remember that we expect many people without (higher) CS degrees. Somebody without information theory background (me included) will not have the association you have.
– Raphael Mod
Mar 14 '12 at 7:38
• That makes sense. I'll change it. Mar 14 '12 at 7:38
• @RanG. Why not use cryptography instead of crypto? If you mean anything bigger than cryptography, computer-security is probably adequate. And I'd rather see one-time-pad than otp. I don't think there's a problem with abbreviations and acronyms, but these just seem sloppy. Mar 14 '12 at 14:20
• I agree. cryptography is the way to go Mar 14 '12 at 16:03
• @Patrick87 I agree, the long names are more clear. I also feel that cryptography is batter than (the well known shorthand) crypto. Can these be updated w/o editing all the questions? Mar 15 '12 at 3:34
• @RanG.: I don't know wether real mods can do that. The way open to us right now is to retag at least one question so cryptography is created, then we can propose a synonym.
– Raphael Mod
Mar 15 '12 at 7:00
• I retagged all crypto questions; the tag was not yet big enough to get this synonym thingy done.
– Raphael Mod
Mar 15 '12 at 7:06

This question was edited by Kaveh to be tagged with . The question does not relate to any algorithm. What should we do?

Pro: Every question should have a tag that relates to a specific area of CS.
Con: The question is far more general than the algorithms tag would suggest.

• I think we should discuss these in separate questions. Mar 14 '12 at 16:00
• I propose to remove the tag. If the majority thinks we should have such a CS-related category tag, it should be algorithm-analysis in this case.
– Raphael Mod
Mar 14 '12 at 16:02
• :) I posted a separate question. ps: The tag tag is sufficient for categorizing questions about tags, no need to keep all of them in one place. Mar 14 '12 at 16:05
• I think that questions like "I am looking for an algorithm for <...>", "What is the name of this algorithm <...>" can be tagged with algorithms, but questions of the form "Is this problem solvable in O(nlogn) ..." should be tagged as questions about computational complexity. Mar 14 '12 at 16:10
• replying here: it is normal to have a number of meta discussions about tags. Keeping all of them in one place will be less effective for discussions (every time an issue comes up people have to check to see what is the issue, discussion will only happen in comments, etc. ) Mar 14 '12 at 16:10
• @Daniil, depends. Is there an algorithm that can solve the this problem in time $O(n \lg n)$ can be a question in algorithms or in complexity theory, or both (as they are not disjoint). :) Mar 14 '12 at 16:12
• @Kaveh that might be a valid point, but unfortunately I am not an expert, so could you please elaborate what does fall into the category of algorithms? Mar 14 '12 at 16:19
• @Daniil, roughly F.2 (and sometime also parts of E.1 and E.2) in here. Mar 14 '12 at 16:24
• @Kaveh: And certainly parts of F.1 (in particular parallel algorithms). I do not think using such a list is particularly useful; no one will have the overview.
– Raphael Mod
Mar 14 '12 at 16:42
• Agree with Raphael, disagree with Kaveh on this one. The question should not have been tagged with algorithms, as it has nothing to do with algorithms, per se, but with their analysis. However, I tend to agree with @Kaveh that there's no great reason to insist all tag-related discussions go here. Better to clutter the question list than to clutter a single question; at least the former is easily searched and ordered! Mar 14 '12 at 16:54
• @Patrick87, those were the ones listed on arXiv for Data Structures and Algorithms category, distributed and parallel algorithms have their separate category on arXiv (DC - Distributed, Parallel, and Cluster Computing). I think for main categories sticking to the something similar to the major categorizations of CS topics by experts is useful for several reasons. I would prefer to continue discussion about this on the separate meta-question. Comments are not design to handle discussions but to be short and brief. Mar 14 '12 at 18:19