user14946: A message appeared in my Inbox informing me that . . . a notice had been attached to one of my accepted answers.  The notice seems to me a comment from a moderator, but as far as I can tell the author is anonymous (I could not read the notice/comment on the mobile App, I had to login using a browser to display the full contents).
I searched through the Help, as well as the Biology Meta posts but could not find any description of these notices.
Is this mechanism documented anywhere? In particular is there a way for me to respond/reply?

user3340: Post notice is a very docile feature which a moderator can use to mark an answer. There are three types of post-notices:

Current event: Marks the answer as one that may not be useful in future. 
Insufficient explanation: Marks the answer to be insufficient in content
Citation needed

These are pretty useless actually (mostly a fancy, templated comment) but can sometimes be used to mark a highly voted/accepted answer which seemingly has one of the above issues, while letting the post remain. Sometimes IMO it can be used as a disclaimer. I don't know about its historical usage in StackOverflow.

user1306: These are canned messages that are available to mods. They are:

You can see who added it by checking the edit history of your answer. In this case, you will see that a notice was added by @WYSIWIG. 
Once you have addressed the issue raised by the notice, you can leave a comment, notifying @WYSIWIG and he can remove it. 

14946: <p>A message appeared in my Inbox informing me that . . . a notice had been attached to one of my accepted answers.  The notice seems to me a comment from a moderator, but as far as I can tell the author is anonymous (I could not read the notice/comment on the mobile App, I had to login using a browser to display the full contents).</p>

<p>I searched through the Help, as well as the Biology Meta posts but could not find any description of these notices.</p>

<p>Is this mechanism documented anywhere? In particular is there a way for me to respond/reply?</p>
 3340: <p><strong>Post notice</strong> is a very docile feature which a moderator can use to mark an answer. There are three types of post-notices:</p>

<ol>
<li>Current event: Marks the answer as one that may not be useful in future. </li>
<li>Insufficient explanation: Marks the answer to be insufficient in content</li>
<li>Citation needed</li>
</ol>

<p>These are pretty useless actually (mostly a fancy, templated comment) but can sometimes be used to mark a highly voted/accepted answer which seemingly has one of the above issues, while letting the post remain. Sometimes IMO it can be used as a disclaimer. I don't know about its historical usage in StackOverflow.</p>
 1306: <p>These are canned messages that are available to mods. They are:</p>

<p><a href="https://i.stack.imgur.com/EImH7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EImH7.png" alt="mod notices"></a></p>

<p>You can see who added it by checking the <a href="https://biology.stackexchange.com/posts/31493/revisions">edit history</a> of your answer. In this case, you will see that a notice was added by @WYSIWIG. </p>

<p>Once you have addressed the issue raised by the notice, you can leave a comment, notifying @WYSIWIG and he can remove it. </p>
