I've seen some folks here mention that they keep film in the freezer.

I take it that's to keep the film from aging as rapidly as it would otherwise?

Also, are there films that really should (and conversely, should not) be put in the freezer to keep them fresh?

In particular I'm thinking of Ilford PanF+ asa50. I've had great luck with it and would hate to see it go away given Ilford's problems.

I'll also want to buy a fair chunk of 9 x 12 cm film once it comes back on the market. Into the freezer with it, too?