Identifier syntax change from 1.3.43 to 1.3.147

[Roy . Rankin]

The following (with appropriate ;'s) ran fine in 1.3.143.
However in 1.3.147 I get the error message below.

Why must identifiers now be alphabetic characters only? 
I find this a huge restriction as I commonly use the syntax below and
have a fair body of work that uses numbers and underscores for clarity
and readability and meaning.

Regards,
Roy Rankin

BTW should the "}" be in the error message?



Sop_v1 = \notes {
        \property Voice.automaticMelismata = ##t
        \property Staff.midiInstrument = "flute"
        \time 4/4
        \key a \major
        \clef treble
        s8 s1 * 11 s4 s8 s8 s4
}

Parsing...
/home/royr/music/lily3/union/ver2/Iu.v1.lp:18:1: error: Identifier should have  
alphabetic characters only:
}