Question about m and k lens terminology

[jmb]

Hi,

I have two pentax smc k mount lenses.  One is 100mm smc-m f/4 and the
other is a 50mm smc-a f/1.4.  I assume the smc-m is a "m" lens and the
smc-a is an "a" lens from what I've read and seen.  What kind of 
markings do the "k" lenses have?

Thanks,

John