A weak jump shift is a jump response to an opening bid bellow 1NT (only if RHO passes). 

• a single jump to a new suit at the 2-level shows 2-5 HCP and a 6-card suit;

1♣ - (P) - 2♦/2♥2♥/♠;

1♦ - (P) - 2M;

1♥ - (P) - 2♠,

• a single jump to a new suit at the 3-level shows 2-7 HCP and a 7-card suit.

1♦ - (P) - 3♣;

1♥ - (P) - 3m;

1♠ - (P) - 3m/3♥.

Further bidding is natural. There is no need for any additional arrangements.

After any RHO intervention, the convention is off (in favor of other conventions, e.g. Fit showing jumps).