The following is quoted from the April,
2016 AWGA Newsletter. under the
title "Handicap Corner"
Q:  Our club is hosting an invitational.  We will have
mulligans and magic putts.  Do we need to post scores?

A:   Section 4 of the USGA Handicap System Manual
contains the following definition:  "The game of golf is based
on the premise that a player will play as well as the player
can play.  Under the USGA Handicap System, each player
is required to record a hole score for a hole not finished, not
played, or not played under the Rules of Golf....:

If the golfer plays at least 13 holes under the Rules of Golf
(seven holes for a nine-hole game) the player must post a
score.  For posting purposes the following adjustments can
be made for holes not played under the Rules:

*Mulligans - post par plus allotted handicap strokes
*Magic Putts - post most likely score
*Free throw or kick - post par plus allotted handicap strokes
*Pro hits a shot for the player - post par plus allotted
handicap strokes
*Hole not finished - post most likely score
*Hole not played - post pr plus allotted handicap strokes

The Tournament Committee must inform participants of
these requirements and must also decide who is to be
responsible for posting the scores.  The committee must
also decide if the scores are to be posted as "T" scores or
regular scores.  Individual golfers are to be aware of the
conditions of competition.

And so, in answer to the above question - if you play, you
post!

References:  USGA Handicap System Manual sections 4-1
and 4-2.    (END OF QUOTE)
"IF YOU PLAY, YOU POST!
RECAP
Magic putts and/or unfinished hole:  most likely score
All others:  par plus pops