21.14.11.3 Description

If this command is used as a –from argument in either the set maximum (set_max_delay), or set minimum delay (set_min_delay), false path (set_false_path), and multicycle constraints (set_multicycle_path), the clock pins of all the registers related to this clock are used as path start points.
If this command is used as a –to argument in either the set maximum (set_max_delay), or set minimum delay (set_min_delay), false path (set_false_path), and multicycle constraints (set_multicycle_path), the synchronous pins of all the registers related to this clock are used as path endpoints.