precedence verified
Creation timestamp, despite the name
Not a priority at all: the engine stamps the moment the profile was created and uses it to keep the console list in a stable order.
In detail
The name invites the obvious reading — higher number wins — and that reading is wrong. A profile created through the console at 16:47:07 came back with precedence = 1789663627, the Unix timestamp of that second, and a second profile created five minutes later carried the later timestamp. Nothing in the console displays or edits the value. It is not how overlapping profiles are resolved, because overlapping profiles are not resolved at all: rules are unique per target and the limits of everything that matches are combined (see mq5.concept.limit-resolution). The column orders the list, and that is all it was observed to do. For Hub the practical consequence is a relief: there is no priority to compute and no ordering to maintain. Write the column as the creation time or leave it at zero; the delivery behaviour does not depend on it.