Sunday Life

[Duncer]

Struggling badly

18 across Points and numbers of fundamental importance (8) C?R?????

19d and 20a It may formally be assumed by the consumer (6,6) ????E? ???K?T

[vegasmad]

18a. cardinal

[imagcq]

dinner jacket

[Mamyalynne]

Cardinal

Dinner jacket

[vegasmad]

19d dinner jacket

[shoota]

19d Dinner jacket

[Duncer]

Dinner Jacket

[Duncer]

Many thanks folks, one to go.

11 across Tell in detail what comes at the end R?L?I?

Is this relief?

[shoota]

Relate?

[Duncer]

I'm pretty sure that 7 down "Surrender and refer to arbitration" is "submit", so the penultimate letter is "I".

[factor-fiction]

Retail?

[shoota]

Relais and rollic are the only words that fit and neither of them fits the clue. Could something else be wrong?

[factor-fiction]

Where does your L come from, please?

[Duncer]

This answer won't be often found R?R??? and I plumped for rarely

[Mamyalynne]

Rarity

[Duncer]

Could very well be mamalynne, but am still stuck on the across which would now be R?R?I?

[shoota]

Does that make it 'Relate'?

[Duncer]

Sorry, that would leave R?T?I? which could, I suppose, be retail, from "about" and "what comes at the end". although it is hardly tell in detail.

[shoota]

No words fit R-R-I-

[Duncer]

By the way, your help has been much appreciated, thanks to all.

[bulliver]

retail - To tell or repeat (gossip or stories, for example) to others

http://www.thefreedictionary.com/retail