Are you sure it's mode A ? that's quite unusual, most of the stuff in the market is Mode B (mid span) which technically means the injector is between the switch and the device.
Afcourse the switch can support both A and B if it is smart enough, maybe that is where the 802.3f comes in?
Right, Mode B is mainly used if you are not powering a device through the switches POE but rather through a Midspan or Injector. The 802.3f is used in an injector.
Found this great article:
http://www.l-com.com/multimedia/whitepapers/wp_Power-over-Ethernet.pdf
So just to sum this up:
I can use a mid-span mode B injector, or a mode A switch to power a hikvision camera as long as it is 802.3f ?