Got a quick question about serial number requirements that I can't find clarification on, the requirement says that the serial number may include a hyphen, does that mean a single hyphen, or can there be multiple?

I ask because I work at an FFL/SOT that makes ammo brass, but we don't really manufacture any firearms and I want to get a few lowers made with custom serial numbers for myself and want to use my children's birthdays.

Obviously having multiple hyphens makes it look better as a date, or can it only have 1 hyphen total.

Such as PJD-09-18-84, or would it have to be PJD-91884?

Thanks

I believe panzer arms and cugir frequently uses double hypens in their SNs.  You should not have any issues.

You could always do the date like

AUG15-1988

or 15AUG1988

More than 1 is OK.

Doesn't matter how many.  Just bear in mind that ATF strips them out in applications like eForms.