class-C designation

[Jim Pazarena]

I have just been assigned a /23 network.
I am used to /24 and referring to it as a "class-C".
Is there a name which may refer to a /23 network? Or must I simply
refer to it a "two back-to-back class-C's" ?

Second question. In a /23, is it permissible for me to use the inner .255/.0 numbers?
The telco told me I could not use them, but it doesn't make sense if indeed they
have routed me a /23.

Thanks,
Jim