When importing you have the option to check "Skip over this category assignment for rows that don't match above."
This means that for any rows that don't match the rules specified, the particular category assignment for that person will be skipped over during the import.
In other words, if this is NOT checked and your csv contains something other than defined in these rules an error will appear and you will have to fix it (by setting it to one of the values specified in the rules) before importing the csv.
In this csv you can see there is a category column for delegate. Also note that the values of the delegate category column are "TRUE" "FALSE" and "YES"
If you were to configure the import for the category like this - you would be prompted to fix one of the rows as there is a row in the CSV that doesn't match the rules (the third last row with "YES"):
But if you were you to check the box to skip over category assignment - the importer will simply ignore assigning a category to the person that doesn't match the rules: