This is basically covered by the faq

https://pm.stackexchange.com/faq#signatures

> ### Can I use a signature or tagline?
>
> Please *don’t* use signatures or taglines in your posts. Every post you make is already “signed” with your standard user card, which links directly back to your user page. Your user page belongs to you — fill it with information about your interests, links to stuff you’ve worked on, or whatever else you like!

I hope you can understand that someone with 500 posts, and 500 distinct "signature" lines -- now multiply that by dozens or hundreds of users -- this is not increasing the signal to noise ratio on the internet, which is one of our goals as an organization.

We do, of course, **encourage you to put tons of information about yourself on your user page**, which is very clearly linked to from every post and comment you make.