Meanings of usual conventions in English

I did not attempt the usual conventions of society, nor did she.

There was something simple and primitive, something of dignity beyond the usual conventions, in his direct address.

But he had no training in the usual conventions, and we must remember that he had no experience whatever of women.

The presidential election was to occur in November, and the nominations had already been made in stormy debates by the usual conventions.

They turn inside-out the usual conventions of dramatisations and archival footage, showing us how cinema has helped build historical events into legends.

It's mitigation time, when one-sided attestation is permitted, without contest; and the usual conventions about evidence, and about the inadmissibility of hearsay, are abandoned.