In Standard ACOL, opening bids of 2♦ , 2♥  and 2♠  can be either WEAK or STRONG.

WEAK
Hands with 6-10 High Card Points (or 5-9 by partnership agreement) and a long suit (6+ cards) should be opened at the 2, 3 or 4-level and should be announced by partner as "WEAK".

STRONG
Hands with 18+ High Card Points and 5+ cards in the suit should be opened at the 2-level and should be announced by partner as "STRONG".

Opening bids of 2♣ (Standard ACOL or BENJI) should be announced by partner as "STRONG and FORCING".

Agreement must be made by partnerships about whether they are playing Strong or Weak 2s and that agreement should be adhered to.