KR: 1. Kind regards. 2. Another in the trite series of acronyms used to save microseconds on email. (see BW; Bz; IMHO; PCB; Tks)
PCB: 1. Please call back. 2. Passing the buck so that the other person has to take action rather then you. (see BW; Bz; IMHO; KR; Tks)
TBU: 1. True but unhelpful. 2. Thanks for pointing that out but it doesn’t help us at all; shut up.
Tks: 1. Thanks. 2. More email time saving twaddle. (see BW; Bz; IMHO; KR; PCB: Tx)
Tx: 1. Thanks. Even more email time saving nonsense. (see BW; Bz; IMHO; KR; PCB; Tks)