User`s guide

Links and Link Types
9-5
Links and Link Types
Requirements links are the data structures, managed by Simulink, that identify a
specific location within a document. You get and set the links on a block using the rmi
command.
Links and link types work together to perform navigation and manage requirements. The
doc and id fields of a link uniquely identify the linked item in the external document.
The RMI passes both of these strings to the navigation command when you navigate a
link from the model.