{!URLFOR($Action.Contract.APXT_Redlining__View_Redlines, null, [altId=Contract.Id, disableOpenInWord=true, disableNegotiate=true, disableTrueUp=true, disableSavePdf=true, enableRecursiveMergeSync=true], false)}

This button code disables True-Up and True-Up All.

{!URLFOR($Action.Contract.APXT_Redlining__View_Redlines, null, [altId=Contract.Id, disableOpenInWord=true, disableNegotiate=true, disableTrueUpAll=true, disableSavePdf=true, enableRecursiveMergeSync=true], false)}

This button code enables True-Up but disables True-Up All.