"v", "xv", and "xx"

[huckdat]

was wondering why,on some helmstetter cues,they have "v","xv", or "xx"on the butt?

and #9 and #14 here
http://forums.azbilliards.com/showthread.php?t=211290&highlight=helmstetter

 

[Jim Baxter]

I think it is a run Number means nothing . Jim

 

[huckdat]

it does make sense,but i wonder that they only put these marks on some of their cues.maybe this was during a certain time frame?