When an instituted acolyte acts as crucifer, wearing the acolyte's tunicle.

Typically this is done either when there are two deacon's assisting the celebrant (and no need for an acolyte) or at a pontifical mass (when the Bishop is celebrating) and there are both an acolyte and a tunicled crucifer.

The tunicled crucifer performs all of the duties of a regular crucifer. In addition the tunicled crucifer acts as paten bearer rather than the MC.