When flagging a post spam because of a single URL considered as spam it may be challenging to find the reason for flag, if the post otherwise is well formed.
For example there seems to be a user creating new accounts and promoting his site. The questions are somewhat related but when you access the link, the site doesn't seem to have the problems mentioned at all. Closer look reveals that the site is for downloading pirated software (or maybe something worse masked to be just that).
Should it be added as a public comment or should there be either optional or even mandatory explanation field on this flag type?