I am assuming that 1
♦ is (3)4+ , so unlikely we will ever want to play in that suit. Therefore:
2
♦ = Usually big hand with support, probably a fit with Clubs but could be a big NT hand without a Diamond stopper.
2
♥ = Larger than average with Hearts, probably 6+ . After all, we can just bid 2
♥ naturally on the first round.
2
♠ = Pretty big hand with Spades. While borderline, I have an example hand of X then a Major below.
I would also say that 2
♥ and 2
♠ should be limited to less than an opening Strong 2
♣ (With HCP, IF it ever comes up), which you can do via 2
♦ and then bidding the Major naturally.
While not the most likely, a hand from a tournament awhile ago convinced me that I needed the Major as natural. Hearts play better than NT, and it's very likely if you bid 2NT instead of 2
♥, partner will raise to 3, going down 1:
"It's not enough to win the tricks that belong to you. Try also for some that belong to the opponents."
"Learn from the mistakes of others. You won't live long enough to make them all yourself."
"One advantage of bad bidding is that you get practice at playing atrocious contracts."
-Alfred Sheinwold