What is BLF? please

[beckzayi]

Hi there

What is BLF? Can anyone help me out?
I did search BLF on google. But, on an IP phone, such as GrandStream, if we set up BLF for the phone, where is the 'BLF' on the IP phone. I notice that normally an IP phone has a screen, and a number of small buttons for the speed dial or something like that. So, where can we see 'BLF' on the phone?

Thanks