[plt-scheme] Naming style

Warning: I am a clueless newbie when it comes to PLT-Scheme (though I
have some slight background with Lisp-like languages).

I've just started glancing at "An Introduction to Scheme with
Pictures", which uses something called "#lang slideshow".  Almost
immediately I see the function "hc-append".  When I go look at the
docs, as suggested, I see that it's one of a family of functions, all
of which follow this naming convention:

    <options>-<operation>

Thus, this command appends pictures together horizontally ("h"),
centering them vertically. ("c").

This strikes me as a very add way to name functions; I'd have thought
that having one function, "append", with arguments indicating the
alignment, would make more sense.  On the other hand, someone
implemented it this way on purpose, and given that it's used in a
document for newbies like me I presume it's good style.  Would someone
care to explain to me *why* it's good style?

Thanks very much.