Hello all...need help, again!

I am sorting documents for my wife's settlement visa application which we plan to apply for in June this year, I need some help regarding supporting documents....

Which documents come under the 28 day rule (i.e. which need to be dated within 28 days of them being handing in to the Embassy.

Is it just Bank statements and Wage slips?..,or does it cover other documents, like the Land Registry title register and letter from my Employer?

Cheers for any advise!