How to add 'codes' part to post?

Its left of the "#" key on the toolbar above where you write your post.

like this or simply by writing

[ CODE ]HI [ /CODE ] without spacing on [brackets]
usually only visible in advanced reply..
The other,( dialogue bubble) ,as you have correctly pointed out is a

Quote

quote tag

Quote

Codar - your name tells you are expert of codes issues...
Thanks for your reply - I think you mean to the "#" key itself but not its left - right?

True, was thinking "quote"