maybe because of characters limitation for newbie rank.
u can read on these thread https://bitcointalk.org/index.php?topic=177133.0

Signature Restrictions:
- Newbie: No styling (including links) allowed. Max 50 characters.
- Jr. Member: Links allowed. Max 150 characters.
- Member: Unlimited length.
- Full: Color allowed.
- Sr. Member: Size allowed
- Hero: Background color allowed

btw im new here too, i wanna ask about campaign too.
can i change/quit my campaign or i have to campaign it for the rest of my life?