any way to apply tag across all branches in repository?

Hi all,

I'm hoping you can help me out...please CC me on replies, I'm not subscribed to the list.

We have a piece of software with a "main" branch and multiple architecture-specific "target" branches. At each "official" compile, we'd like to tag the commits that went into that compile with an identifier.

Using tags normally requires that the tag be assigned to each branch individually--is there any way to apply some sort of designator to the head of each branch in the repository all at once rather than doing it separately for each branch?

Thanks,

Chris