What is mean by validation, re-validation, co-validation, and cross-validation?

[@sivaramach1]

I think we need to validation for the new addition of Impurity only., through addendum

[@abhaypatil823]

When all process of Formulation is same but change in source of API ( vendor change) then what parameters to be performed in re validation?

[@bihariaehshankhan7447]

What is different between usp and usp-nf ?

[@amritarajput2597]

Is cross validation and methods equivalency are the same

[@tadalavenkateswararao2090]

Sir which parameters performed in at the time of method transfer and is it any differences in acceptance cretirias inthe validation and method transfer same parameters is it acceptble?

[@karnakarkadaru2317]

Sir make a full video on method transfer