Should I implement response to "HEAD" request?

Hello,

I'm writing client-server application that should communicate through HTTP
protocol. It is not a web-server. My application just use HTTP as a
transport.
I never send HEAD request myself. So I don't implement any response for it.
Should I do it?

1. Can some proxy server on the way between my client and server use this
request for some optimization purposes?

2. Is it actual without caching? I use "Pragma: no-cache", "Cache-Control:
no-cache" in every requests.

SY, Alexey.