I would like to know what is the policy of the "official orthodox churches" (Constantinople, Moscow etc) regarding weddings between their faithfuls with faithfuls from "true orthodox churches" (those belonging to old calendarist jurisdictions, Russian true orthodox churches etc), and we could add old believers. The aim of the question is not polemic, I am myself a "true orthodox" but more informational because I see nothing about this and when I ask the question, I generally get no clear answer. However, I guess that the question for sure must have arisen in countries like Greece, maybe Romania or the US.
I see that most official churches, since the 17th (for Russia) and 19th century (for Greece) conduct wedding between their members and other christians baptized in the name of Trinity, under condition the children will be raised as orthodox (condition that it is not always respected by the way). The exception regarding the practice is the church of Georgia that follows the traditional canonical order, only marrying orthodox with orthodox. But none of them explicitly deals with the question of orthodox they would regard as schismatics.