Your notrump range is 15-17. 2C was alerted and explained as "diamonds OR a major-minor two suiter". 2H is a transfer by agreement (your hand: Q9xxx JTxx Txx x). You have no agreements re. superaccepting in competition. Should the "default" agreement here be:
1. Natural, no implications regarding spade fit
2. Natural with a fit
3. superaccepting with stuff in diamonds
4. advance control bid superaccepting spades (more slammish than 3 I guess?)
5. something else
?