Most of good impact journals have strict policies for plagiarism.However going through review of literature or introduction chapters,some times certain lines appear in a repeated manner which can be even from your own published articles and this also leads to plagiarism .
My question is that do various generals evaluate the plagiarism in submitted manuscripts separately for Introduction ,M&M, Discussion etc.
If it is so, what is permissible % range which falls below plagiarism definition for each category.
or
If the whole manuscript is evaluated as a single piece,what is the limit in terms of % in that case?