CRASH
Over 1N


Dbl is penalty if by an unpassed hand.

2 (H or S) is natural and one-suited.

2 shows two suits of the same Color.

2 shows two suits of the same RAnk (both majors or both minors).

2N shows two suits of the same SHape (both pointed tops, Spades and Diamonds, or both rounded tops, Hearts and Clubs) -- but only by an unpassed hand in direct overcall position.

By a passed hand or in balancing position:
Dbl shows two suits of the same shape.


NOTE:

The ACBL General Convention Chart says:

    Under "COMPETITIVE - #3": 
      A notrump overcall must be for one of the following: 
      • (a) A two-suit takeout showing at least 5-4 distribution and at least one known suit
        (At the four level or higher there is no requirement to have a known suit.) 
        OR 
      • (b) A three-suit takeout (at least three cards in each of the three suits.)
    Under "COMPETITIVE - #7b": 
      Direct overcalls of 1NT must have at least one known suit EXCEPT for: 
      • Double 
      • 2 
      • 2 showing a one suited hand in hearts or spades

CRASH's 2 bid shows either both majors OR both minors.
This does not meet #3a, above since there is not a known suit.
It also does not meet the exception in #7b3 which applies only to 2 showing .

So it appears that CRASH is not allowed by the ACBL. An alternative is SCuM.