This is my proposed list of canned comments. Feel free to post a list of your own as another answer, or propose more additions in the comments.
Untagged
These won't have any special tags to them, so you'd be able to use them everywhere; under both questions and answers.
### Formatting
Please visit [the help center](https://ell.stackexchange.com/help/formatting) and [our formatting guide](https://ell.meta.stackexchange.com/q/996/) on how to format your future posts better.
Tagged [Q]
These will be tagged [Q] in AutoReviewComments, and will appear when you want to comment under questions.
###[Q] Proofreading
Unfortunately, your question is worded like a proofreading question. Proofreading is off-topic on ELL, and that would make this question eligible for closure. Please [limit your question to a specific area of concern](https://ell.meta.stackexchange.com/a/260/), or consider [Alternative websites for proofreading](https://ell.meta.stackexchange.com/q/263/).
###[Q] The "grammar" tag
Please don't use the [tag:grammar] tag on your future posts. It's an officially [deprecated tag](https://ell.meta.stackexchange.com/q/3332/). See also [A proposed solution to the "grammar" dilemma](https://ell.meta.stackexchange.com/q/2706)
###[Q] Details, please
Your question seems to lack crucial context required for answering it. [To prevent wrong and incorrect answers, please include more details](https://ell.meta.stackexchange.com/q/439/) of where you've encountered this or attempt to use it. Otherwise, this question may get closed. See also [What should I do when I saw a phrase or sentence I don't understand?](https://ell.meta.stackexchange.com/q/1084/)
###[Q] Rash accept
It would be nicer if you held back on accepting an answer for a while, not to discourage further good answers from being added to your question. See [Not so fast! When should I accept my answer?](https://ell.meta.stackexchange.com/q/1307/)
Tagged [A]
These will be tagged [A] in AutoReviewComments, and will appear when you want to comment under answers. Shamelessly stolen from SOBotics
###[A] Answers just to say Thanks!
Please don't add _"thanks"_ as answers. They don't actually provide an answer to the question, and can be perceived as noise by its future visitors. Once you [earn](http://meta.stackoverflow.com/q/146472) enough [reputation](http://$SITEURL$/help/whats-reputation), you will gain privileges to [upvote answers](http://$SITEURL$/help/privileges/vote-up) you like. This way future visitors of the question will see a higher vote count on that answer, and the answerer will also be rewarded with reputation points. See [Why is voting important](http://$SITEURL$/help/why-vote).
###[A] Link Only Answers
A link to a solution is welcome, but please ensure your answer is useful without it: [add context around the link](//meta.stackexchange.com/a/8259) so your fellow users will have some idea what it is and why it’s there, then quote the most relevant part of the page you're linking to in case the target page is unavailable. [Answers that are little more than a link may be deleted.](//$SITEURL$/help/deleted-answers)
###[A] NAAs by < 50 rep
This does not provide an answer to the question. You can [search for similar questions](//$SITEURL$/search), or refer to the related and linked questions on the right-hand side of the page to find an answer. If you have a related but different question, [ask a new question](//$SITEURL$/questions/ask), and include a link to this one to help provide context. See: [Ask questions, get answers, no distractions](//$SITEURL$/tour)
###[A] NAAs by > 50 rep
This post doesn't look like an attempt to answer this question. Every post here is expected to be an explicit attempt to *answer* this question; if you have a critique or need a clarification of the question or another answer, you can [post a comment](//$SITEURL$/help/privileges/comment) (like this one) directly below it. Please remove this answer and create either a comment or a new question. See: [Ask questions, get answers, no distractions](//$SITEURL$/tour)
###[A] 'Me too!'
Please don't add _Me too!_ as answers. It doesn't actually provide an answer to the question and can be perceived as noise by its future visitors. If you have a different but related question then [ask](http://$SITEURL$/questions/ask) it (reference this one if it will help provide context). If you're interested in this specific question, you can [upvote](http://$SITEURL$/help/privileges/vote-up) it or leave a [comment](http://$SITEURL$/help/privileges/comment) once you have enough [reputation](http://$SITEURL$/help/whats-reputation).
###[A] Question posted as answer
This post isn't an actual attempt at answering the question. Please note [$SITENAME$ doesn't work like a discussion forum](http://$SITEURL$/about), it is a Q&A site where every post is either a question or an answer to a question. Posts can also have [comments](http://$SITEURL$/help/privileges/comment) — small sentences like this one — that can be used to critique or request clarification from an author. This should be either a comment or a [new question](http://$SITEURL$/questions/ask).
###[A] Editing NAA in review
Please don't edit those posts that aren't answers. Editing in review clears the current flag and stops the deletion process. You should "Recommend Deletion" instead, or Skip if you're not sure.
###[A] Editing VLQ in review
Please don't edit link-only answers when you cannot salvage them. As is, they aren't answers and should be deleted. Editing in review clears the current flag and stops the deletion process. You should "Recommend Deletion" instead, or Skip if you're not sure.
###[A] Duplicated answer to multiple questions
Please don't add [the same answer]([type here]) to multiple questions. Answer the best one and flag the rest as duplicates. See [Is it acceptable to add a duplicate answer to several questions?](http://meta.stackexchange.com/q/104227/347985)
Tagged [C]
These will be tagged [C] in AutoReviewComments, and will appear when you want to compose a close-as-off-topic reason message.
###[C] Writing advice
I'm voting to close this question as off-topic because it's writing advice. See [help center](https://ell.stackexchange.com/help/on-topic) to learn more.
###[C] Typo
I'm voting to close this question as off-topic because it's a typographical error. It's too localized to be helpful to future visitors.