A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.

indicates that your question is about site policies. Usually, new proposals for policies or questions about existing ones will have this tag
For questions about code golf challenges and/or submissions. DO NOT post code golf challenges themselves as questions here; those belong on the main site or in the Sandbox if you want to get feedback …
For questions regarding answers posted to challenges. This tag is not for questions about a specific answer, but for answers in general
178 questions
keywords or labels that categorize and group your question with other, similar questions.
For questions about scoring a challenge or how to score a particular language
77 questions
76 questions
For meta questions pertaining to asking other questions, on main or meta.
proposing new rules or asking for clarification on other ones.
74 questions
a place where you can post proposed challenges for others to review.
Requests for help with, or discussion of, a specific question on CGCC.
64 questions
about features and discussions that specifically relate to new users on the site.
For questions about using the Stack-exchange chat system
For questions regarding challenges on main. This tag is not for questions about a specific question, but for questions in general
44 questions
For questions that relate to the reasons behind closing a challenge/challenges
Questions about the "close as duplicate" mechanism.
41 questions
For questions that relate to the quality of challenges on the main site
appropriate for PPCG.
34 questions
For questions about up/down-voting posts. Not to be confused with close, reopen, deletion, or election votes.
34 questions
For questions about editing - both when and how editing is done on either main or meta sites
either proposing or asking for clarification on winning criteria.
Questions and discussion related to CGCC Meta itself, not just CGCC. Questions with this tag should specifically relate to Meta and not to the main site
Questions about moderation of this site, including the site moderation tools, policies on moderation and specific moderating actions taken by users
General questions about questions that have been closed because they do not meet the criteria defined in the FAQ.
27 questions
the most frequently asked and answered questions on Meta and the first place to look for answers to your questions
For clarification of rules that apply to challenges if not mentioned by the author
27 questions
a way for any user with 15 reputation or more to alert the site moderators about problematic posts. Use this tag on questions that directly relate to the flagging system and flags as a who…
23 questions
Each month, we select a "language of the month" - a programming language that isn't as well used on the site - in order to promote usage of that language. This tag is for questions relating to the Lan…
the system used by Stack Exchange to measure the values of a user's contribution to the site. As users gain more reputation, they are trusted with more privileges that help the users mod…
23 questions
For questions about the commenting system, such as how it works and what the appropriate usage is
21 questions
A way to attract attention to questions and answers by offering some of your own reputation as a reward to an answer
21 questions