Information about the patterns system as a whole is available at the Specification Patterns Home Page.
There are two basic order-related patterns:
Chain patterns are used to express requirements related to complex combinations of individual state/event relationships. These include precedence/response relationships consisting of sequences of individual states/events. We call these chain patterns.
There are two variations of chain patterns:
A variation of the chain patterns is to constrain the regions between the state/events that constitute the chain sequences.