My brokerage labels stocks that way when they are difficult to borrow for shorting purposes. So yes, usually a good sign unless you would like to / are shorting.
It means my brokerage just stopped allowing short orders for FFFC. Every brokerage has its own HTB list, and not all of them show the HTB sign (with some brokerages one needs to actually place a test short order to find out). So, I guess, it is definitely a good sign, especially if other people with different brokerages are seeing the same thing. I have S*chwab.