MOCs, the HEALPix-based Multi-Order Coverage maps, are a powerful tool
for representing arbitrary shapes on the sphere with user-selectable
fidelity and remarkable compactness. Their most salient feature is that
operations such as union and intersection, nightmarish with conventional
geometries, are just a few lines of readable code with MOCs. This makes
MOC support a natural complement for the Virtual Observatory's Astronomy
Data Query Language ADQL. Indeed, the latest version of the ADQL-based
Registry discovery protocol RegTAP already makes use of MOCs. This
poster describes some proposed ADQL extensions to make MOCs even more
useful in TAP and ADQL and discusses these extensions' implementation
status.