I keep harping on you to visit this website and read it's content. Last Friday during the "Balancing" lesson there was a question about a specific auction sequence [1♦ - P - P - 2♥??]. The question was "Why 2♥ is not interpreted as 'preemptive?"
The answer was there for the last 3 months on the "Play and Lean Page"
Want to Learn how to Count? OK Go to "Your Bridge or Mine Page" and get immersed!
LAW 48 ‐ EXPOSURE OF DECLARER’S CARDS
A. Declarer Exposes a Card Declarer is not subject to restriction for exposing a card (but see Law 45C2), and no card of declarer’s or dummy’s hand ever becomes a penalty card. Declarer is not required to play any card dropped accidentally.
B. Declarer Faces Cards 1. When declarer faces his cards after an opening lead out of turn, Law 54 applies. 2. When declarer faces his cards at any time other than immediately after an opening lead out of turn, he may be deemed to have made a claim or concession of tricks (unless he demonstrably did not intend to claim), and Law 68 then applies.
Law 45C2: Declarer is deemed to have played a card from his hand if it is: (a) held face up, touching or nearly touching the table; or (b) maintained in such a position as to indicate that it has been played.