OE no reference in part A whatsoever I'm afraid. Here is what airbus says:
PROCEDURES
The terminal procedure (RNAV SID, RNAV STAR, RNAV TRANSITION, ...) must be loaded from the FM navigation database and checked for reasonableness, by comparing the waypoints, tracks, distances and altitude constraints (displayed on the F-PLN page), with the procedure chart.
The flight crew must not modify the procedure, that is loaded from the navigation database, unless instructed to do so by the ATC (DIR TO, radar vectoring, insertion of waypoints loaded from the navigation database).
Well there we go again typical Airbus saying lots and nothing. Basically NO but if needed can be done, blah blah... On various occasions discrepancies of different severity between the charts and the box were detected and modified to match the chart version. Is it constructing, amending or whatever? I guess depends very much on the particular situation. One thing is for sure though RNAV IAP is not ought to be modified. In case of a doubt say NO.
