"TFTP Server" field on DHCP server page does not allow hyphen character.
Entering a host name with a "-" in it gives a generic "Please match the requested format" error, for the "TFTP Server" field on the DHCP Server configuration page. It should be considered a legitimate character.
(Pedantically, maybe it's the "dash" or "endash" or "minus sign" character? Not sure. Same key as the underscore on a US keyboard, though it's probably already clear what it is.)
Updated by Shane Poteet about 5 years ago
This still does not have the necessary functionality as it did on 2.2.x as of 2.3.1-5. I need to be able to populate this field with a URL and it is still not taking it, well not if I don't edit and import config. example "http://p.phonism.com/m" or "tftp://192.168.210.1" etc. A URL is required for devices such as polycom.