Locating the code for 'create an account or sign in' message

[JTrollerb123]

Hi, I'm looking to add the following guest messaging - currently appearing to guests at the bottom of each topic and bottom of every article - To a custom block that shows only to guests - Where do i find the code for this so I can replicate?  Thanks!

[opentype]

“guestCommentTeaser” is the template name. 

[JTrollerb123]

thanks!!