Clarify the use of a leading wildcard

[sustr4]

The PSL Specification says:

The wildcard character * (asterisk) matches any valid sequence of characters in a hostname part.

Perhaps a clarification of the term valid sequence is required. I am facing an issue with my registered suffix *.cloud.metacentrum.cz. The DNS name of the front-end machine cloud.metacentrum.cz is found matching the PSL, even though only names one level deeper are supposed to match. I have had this reported, plus I have tested this myself with the C and Ruby implementations.

Is this something that could fixed by modifying the record in PSL? Or otherwise? Thank you.

[sleevi]

Dupe of #145

[sleevi]

Er, sorry, that should have been #694 for the more narrow case being raised here.

TL;DR: Known implementation divergence. The PSL itself hasn't been able to resolve which is "right", as both interpretations carry some risk.