Old School Singleton follows the Pacific Old School Rules with the following exceptions:
Each deck must contain at least 60 cards and be singletons (i.e. not more than one of any card) with the exception of basic lands. There are no sideboards in Old School Singleton.
The following cards are banned in Old School Singleton:
Errata for Ring of Ma'rûf
Ring of Ma'rûf may be used to get any card you own from outside the game that is legal in PAC rules. This includes cards that are banned under the above deck construction rules (except ante cards) or another copy of a card that you already have a copy of in your deck.