The required id element enables the unequivocal identification of an institute location and thus can improve the communication between learning provider and target organisation.
The definition of the id is completely up to the Learning Provider - apart from datatype and multiplicity, no constraints are enforced. This implies that a provider is free to change an id at will. One should exercise this possibility with caution: it is considered bad practise to modify a previously published identifier: an LMS, e.g., will heavily rely on the consistency of such an element. A Provider should only change published ids after consulting all affected users.