If I want to write a comment that refers to a different stack exchange, what syntax do I use? The exchange I would like to refer to is https://academia.stackexchange.com/ and I only want to refer to it in general, not to a particular question on Academia.
Is there a better place I could have asked this question? Is there a meta site that applies to all of Stack exchange?
Use [academia.se], with the first part of the URL as the first word. That transforms into "Academia", which is the official name of the site and its link, all formatted automatically. This can be done for any site, but some have slightly different syntax. See Magic Links on Meta SE for more info — there are other useful shortcuts!
Note that Magic Links like this only works in comments.
Law Meta (a "child" meta) is the only place where questions about moderation or policies exclusive to Law can be asked. All sites (with very few exceptions) have their own child meta for the same purpose. General questions like this one (where the answer is the same no matter what site it applies to) are also fine on child metas. Meta Stack Exchange is more useful for searching for general answers, however, since it's very comprehensive (so comprehensive, this question would be a duplicate).
Is there a meta site that applies to all of Stack exchange?
Have a look at MetaSE.
The tour says it is for...
...meta-discussion of the Stack Exchange family of Q&A websites.
And...
...is for conversations about problems and ideas that affect the whole network.
what syntax do I use?
When I refer to another Stack, I use the wording from their URL and have not had any feedback to the contrary.
For example:
