It looks like I was wrong in guessing USPSA rules might apply. It looks like this rule from the USPSA MG rule book would apply assuming INMG is not going with some form of wildcat rules.
MG 5.2.5.3:
Due to the varied equipment requirements in a multi-gun match, belts, hol-
sters, belt-mounted magazine holders and speed-loading devices and any
other equipment worn or carried by the shooter may be changed, reposi-
tioned or reconfigured between stages, provided that such reconfiguration is
compliant with MG-5.1.7, and all equipment is in a rules-compliant config-
uration prior to the start of the shooter’s attempt on the Course of Fire.
Here is a link to MG rules.
http://www.uspsa.org/rules/2012_Multigun_Rules.pdf