With two suits of five cards each, there are a number of conventions available.
With the Minors. We use the Unusual 2 No Trump for some two-suited hands. It's most often used for the minors over a major suit opener, but it works just as well over a 1NT opener by RHO.1NT - 2NT Thus is not an alertable bid by your partner. Opponents are assumed to hear such unusual bidding
With a Major Plus . . . Our system uses the Brozel Convention in the direct overcall position - not in the balancing position. It is based on competing with one long solid suit or with two five card suits.
and should ask if they don't know what it means.
1NT - 2D A conventional call -- Brozel - - but it doesn't mean (only) a Diamond suit.