What accusation of code violation might be due against a magus (of Mercere) who:
Gathering mundane coins through ordinary trade, in bulk, uses magic to assess their justness, melt overly debased coins to their metals (which would be most of them), remixes the coins to a high sterling standard, and remints them with the markings of a mundane minter - which is to say, uses various dies to make them seem mundane. These are then recirculated.
Although the minting uses convincing marks, the coins are recast to be perfectly round, and to have rondels on rims, to discourage clipping.
Extra debasing copper is retained, to alleviate costs. The result is that fewer coins are entering circulation than before, but the net weight of silver is the same. The magus keeps careful books and retains none of this silver for himself. A covenant craftsman and some enchanted tools are used for speed and to lower mundane costs - an enchanted crucible and enchanted die stamp.
The goal of this (not that the Tribunal is likely to care) is to improve the quality of silver coinage, to facilitate trade and confidence in coinage, and to be sure that the silver spent by Redcaps is considered just and sound. The magus is involved in commercial trade - he profits indirectly by improving the perception of his silver.