A question about the PMX format[SOLVED]

[A tiny mouse]

I was in a conversation about PMXE rules on a Discord server and somebody mentioned that you need a license to implement the PMX format in other software. Another person said that you need a license only if you want to implement a modified version of the PMX format.
Am I free to implement PMX support or a software that exports to PMX?
EDIT: I found a GitHub doc by NorthPole-P (the author of PMXE) that PMX is free to use and implement for non-commercial uses as long as no changes are introduced in the format.