Are links allowed in the Upgrade Notice section of a plugin’s readme.txt file?

I haven’t confirmed the behavior of the Plugins admin screen, but using the official readme.txt validator, I see that the validator has stripped away the link that I put into the Upgrade Notice section. Judging from that, it looks like the answer is no.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)