Trees
From Voice of the Proletariat
The "tree" is an often-seen format for side-notes outside of the context of a normal comment.
The format of the "default" tree is as follows:
\ -\ --\ |
Each line may have a comment on it that may tangentially relate to the main body of the comment posted, or possibly be a relation of one's personal experience with the matter at hand--or may be entirely unrelated.
Other formats of "trees" exist.
'Trees' were originally developed as a protest against the 'slashie' method commonly employed for the same purpose on TOS, but most people use slashie's anyways.