2 suited support

3♣:  Both RED suits
3♦:  Both Majors
Open 2♦ rebid 3♣: Clubs & Hearts
Open 2♦ rebid 3♦: Diamonds & Spades

With Spades & Clubs: Open 1♠ rebid Clubs
With Both minors: Open 1♦ rebid Clubs.

B. Opponents open the bidding with 1 of a suit - now all pairings for the remaining suits can be shown as follows

(i) 6-7LTC

2N:                         Highest + Lowest unbid suits
Cue-bid:                  The two highest unbid suits
1N and 3♣ rebid:      The 2 lowest unbid suits

(ii) 4-5LTC

Jump cue bid in opponents minor  opening:           Both Majors   
3mi': when opened with the other minor:               Shows the minor bid + Spades
3mi when opponents open in a Major:                  Show the minor bid & the unbid major
The lowest 2 strong :                                                            O'call 1NT then rebid 2H or 3H

C. Protective position when LHO opened 1 of any suit

Now bidding the lower of your 2 suits cyclically shows the suit and the next higher.
Ex:  1♠-P-P-2♦ red suits; 1♥-P-P-1♠ ♠+C   etc.
With a fairly balanced hand without 2 suits use Protective Double asking partner to choose his suit.

Notes: If you have a 6+ card single suited hand make a jump in it.  1D-P-P-2♥
With a fairly balanced hand with values in the opponents suit cosider 1NT - this is not a strong bid. Partner may make a transfer to take- you out of 1NT. This option means that our multi 1N o'call only applies in 2nd position.

D. Defence to opponents opening of 1NT

We use CDH.
Note this modified in the protective position to show the minor bid and a higher ranking suit or suits. 2 Hearts shows 5+ Hearts and 2♠ shows 5+ Spades.

Rusinov can be used in 2nd position only to show 2 suits when 4-5LTC by transfering first to the higher ranking suit and then bidding the second suit at your next  bid.

E. Responding to partners' T-O *

With (7)8+ HCP and 2 suits at least 4-4 bid the lower ranking cyclically at the next bidding level.
Important Note: If your RHO has passed and you hold the lowest 2 unbid suits you must first respond 1NT and on partner'e 2♣ inquiry bid 3♣ which signifies the 2 lowest suits.

F. Opponents have pre-empted at the 4-level

4NT shows the lowest 2 unbid suits.
Double suggests the 2 higher ranking unbid suits