In releases of Maple up to and including 9.5, the _seed variable was used to store the state of the random number generators created by rand.  However this use of _seed has been deprecated and its special meaning may be removed in future releases of Maple.

Instead of using _seed, use randomize, RandomTools[SetState], or RandomTools[GetState].

Currently assigning to _seed or reading the value assigned to _seed will raise a warning.  However, the assignment will cause the state of the random number generator used by rand and RandomTools to be seeded from the given value.  As well, the value returned by a read from _seed will be a valid state that can be re-assigned to _seed.