Most grimoires focus on a single Rune (often narrowed to have some defined subset of the Rune) and contain formulae detailing permutations and combinations of that Rune with the four sorcerous principles. - HQ:G
Pavic Grimoires are limited to the City boundaries, no? The picture of The Master of the Faceless Kings (P:GtA page - 366) shows numerous runes associated with The Rubble. Will this allow spells using all of these runes to be created, but only workable in the city?