The Plaine & Easie Code is a library standard that enables entering music incipits in modern or mensural notation.
Plaine & Easie version 1 is the current accepted version of the specification.
Plaine & Easie version 2 specification is under preparation. It is due to contain significant backwards-incompatible changes, and should not be used until it is finalized.
Encoding guidelines for Plaine & Easie are also in preparation.