Crossword Genius

Conventions where you may make a declaration (7)

Ross

I believe the answer is:

customs

I'm a little stuck... Click here to teach me more about this clue!

This could be a double definition.

'conventions' is the first definition.
The definition and answer can be both acts as well as being plural nouns.
Perhaps they are linked in a way I don't understand?

'where you may make a declaration' is the second definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.

Can you help me to learn more?

(Other definitions for customs that I've seen before include "Import duties" , "Import/export duties" , "Accepted practices" , "Traditions" , "Traditional ways" .)

I've seen this clue in The Irish Independent.
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