Why were early PCE Hucards numbered?

[James8BitStar]

I have an import PC-Engine with about 12 games, seven of which are hucards, and there is one thing I don't understand: Most of the hucards have a "Vol. ##" on their labels. Neutopia is Vol. 34, PC Genjin is Vol. 28, etc.

What's up with this? Were early PCE games available only through subscription or something?

[Aussie2B]

You might find this topic useful:

http://www.digitpress.com/forum/showthread.php?t=21729

Anyway, the volume numbers are present on all first-party Hudson games. That's about it. There's nothing else special about them, and they could be bought normally in stores like anything else.