I've actually been doing that for the last couple of weeks. the normalizing that is... well ratings, categories, and character names..
start with a custom column that the rating is put into and have FFF plug-in put the rating there. I called mine agerange
Custom column example:
Lookup Name: agerange
Column Heading: Age Range
Column Type: Comma separated text, like tags, shown in the Tag browser
Plug-In instructions:
select to configure the plug-in
go to custom column tab
set the name of the column to Rating using the drop down list
not sure of how much of those two parts you needed but figured it couldn't hurt to put them there
Then you can put this in the [Defaults] section of the personal.ini (I have it just before the websites start listing):
add_to_replace_metadata:
rating=>^15$=>PG-13
rating=>^Adult Only$=>NC-17
rating=>^Everyone$=>G
rating=>^Explicit$=>NC-17
rating=>^FR7$=>G
rating=>^FR13$=>PG
rating=>^FR15$=>PG-13
rating=>^FR18$=>R
rating=>^FR21$=>NC-17
rating=>^G - General Audiences$=>G
rating=>^General Audiences$=>G
rating=>^K$=>G
rating=>^K\+$=>PG
rating=>^M$=>R
rating=>^Mature$=>R
rating=>^NC-17 - No One 17 and Under Admitted$=>NC-17
rating=>^Not Rated$=>Unrated
rating=>^PG - Parental Guidance Suggested$=>PG
rating=>^PG-13 - Parents Strongly Cautioned$=>PG-13
rating=>^R - Restricted$=>R
rating=>^T$=>PG-13
rating=>^Teen And Up Audiences$=>PG-13
rating=>^Teens \+$=>PG-13
rating=>^Teens$=>PG-13
rating=>^Young Teens$=>PG
rating=>^X - Adult: No readers under 18\. Contains Graphic Adult Themes/Extreme violence\.$=>NC-17
that covers most of what I have found and normalizes them to MPAA ratings: G, PG, PG-13, R, NC-17, and Unrated. Obviously edit and change, or add, what you want/need and it will normalize the ratings as you download/update fanfics so you don't have to do it manually. :)
there are some sites that do not include a rating so I have been trying to figure out how to get them to identify as Unrated but haven't gotten this figured out yet. If anyone knows how to do that it would help.