Crows Feet diagrams are used by System Architect and other ERD tool sets to show the cardinality and the type of relationship between two entities.

Line endings give the cardinality

Line Ending	Meaning
	has a cardinality of 0 or more
	has a cardinality of 1 or more
	has a cardinality of 0 or 1
	has a cardinality of exactly one
n to n1..n2	has a cardinality of n to n1 to n2

Line types give the nature of the relationship.

Line Type	Meaning
	is an identifying relationship
	is a non-identifying relationship