[CentOS] About yum..

CentOS specificly, is there any rule of thumb about package names when 
searching for and installing things using yum?  I ask, after I finally 
found the perl/Tk package I needed, but only after trying several 
incantations of the package name, from the full blown alpha/numeric name 
to simply perl/Tk.  Is it safe to assume when searching or yum'ing a 
package that just the package name and perhaps up to the release version 
would apply in a majority of cases?

Many thanks...

-- 
Snowman