spaces in package version

[H. Nanosecond]

Hi, 
I encountered pavuk-0.9pl24 a url download utility,
it has a space in the  version name in the Init:
AM_INIT_AUTOMAKE($PACKAGE, "$VERSION  $host_alias")

and this made make distcheck choke from not quoting in shell commands.
So my question is what is the ruling on spaces in version names?
Allowed or disallowed? 

thank you.