# Can I create a mouseover summary or documentation for a new function?

In Mathematica, when you hover any a built-in function, a small window with 2 symbols appears (as in the third paragraph of this reference page, see picture): clicking on the former one gives you a quick description of the function ("summary"), whereas the latter is a link to a detailed page on the function ("documentation").

My question is if it's possible to do exactly the same on a function defined by the user.

(source: wolfram.com)

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• People here generally like users to post code as Mathematica code instead of images or TeX, so they can copy-paste it. It makes it convenient for them and more likely you will get someone to help you. You may find this this meta Q&A helpful – Michael E2 May 18 '16 at 15:40
• – rm -rf May 19 '16 at 18:13

You can do it by using the MessageName operator (::). Here is an example.