In my last post I discussed how after the opponents bid 2 suits:

(1X)-P-(1Y)-?  2X and 2Y are both natural.

You should also discuss 1N with your partner.  I play it is strong.  Why? 

These days people open garbage and respond on garbage, so it can still be our side's deal.  I sometimes even have the auction: (1X)-P-(1Y)-1N-(P)-3N  [and make it]

But now I would like to discuss more foundations for balancing, as some players confuse agreements about direct action when balancing.

(1Y)-P-(P)-?

What is the range for 1N?  2N?

What kind of hand strength do you need to bid at the 1 level?  2 level?

What about 2Y?  or jump-shifts?  or double?

The first answer to all of these questions, is that the hand is likely to be ours.

Most importantly: our bids are aimed to be constructive, not destructive.

So...  2N is NOT 2-lower suits, but about a heavy 2N rebid - maybe 18+ to 20-

1N is 10-15 (some play a tighter range), and with 16 to 18-, start with double.  Also, Txx or Jxx is usually good enough to stop.  Part can jump cuebid next to force to 3N but check for a real stopper.

(over the 10-15 1NT, most play a modified version of stayman, that includes a min/med/max range ask)  Also most play 4-way xfers still on.

2Y is still Michaels, but instead of being weak or strong, it is medium -- about opening bid strength.

2X lower than Y is a little lighter than a normal 2 level overcall - maybe a King or so, but in that case, have a good suit.  (you can always bid 1N with a bad 5-card suit)

2Z higher than Y - a jump shift -  not weak but intermediate.  A suit which would pass the vul weak 2 standard in a hand that would open the bidding and be in-between bidding 2 or 3 over 1N.  Looking for a game if partner has fitting cards.  The same is true for 3X lower than Y.

3Z higher than Y - a double jump shift - partnership agreement.  Some play it is even stronger than the single jump shift.  An opening which would rebid 3.  But others start with double on that hand, and use the double jump shift to show strong 2 suiters.

Simple 1-level overcalls are probably similar to in direct seat, but with a weak hand, the odds of LHO being strong go up, as partner did not act...  so don't be afraid to pass.