[SpicyLemonZest]

Managers and supervisors are not protected by the NLRA, so whether they might like to provide a reference isn't really a matter of concern for the NLRB. (In practice, managers provide references informally all the time, and I can't imagine a company actually taking action against them for that unless the reference causes some huge problem.)

[giantg2]

I know a manger at my company that provided a reference and was reprimanded for it. They even told him I'd he ever does it again, he's fired. I heard of at least one other manager who was actually fired.

[ghaff]

If there were a formal company policy, I'd probably either demure or, if I felt strongly about it, make sure it was over beers at the bar or in some other venue that there was no record.