I've seen some members on ATRL have this text under their username like these for example:

Jᴜɪᴄʏ & Sʟɪᴘᴘᴇʀʏ
ᴄʟᴀssɪᴄ
ɪᴍᴘᴇʀғᴇᴄᴛ ᴀɴɢᴇʟ

Those are examples now does anyone know?

Those should help some ATRL members who were curious to know how to do these type of texts.

http://fsymbols.com/generators/smallcaps/ I use this.

Thanks

Yep.

There's also plenty of symbols and other text letter things (but they're more spacious and all) on there. It's good for decorating and sprucing up your posts/signature/etc. a bit.