I know that for the rated duty position it has to be what you are working in. Now, If you are working in a position junior to you then what next? Example: I am a 13F4P the Rated duty position I work in is 13F3P. Is this somthing I have to accept or can I be rated as a 4 position. The problem is the time I do now does not count as rated time I will need for the next positon. I have yet to find somthing in AR 623-205 and AR 623-3 that deals with this. The next qestionn related to this is I perform an addintional duty as a 11B4 should I have this as my rated duty position or what?

you should be rated for the slot that you are holding....now unless you've made some kind of deal with your rater (which i've seen before) is something else...also, no, your additional duty shouldn't be your rated position...w/e your position is on the UMR then that should be your rated position

How do you perform an additional duty as an 11B40? As for the rated duty position I don't think I've ever seen someone get rated at a lower position, but then again my MOS is so shorthanded that I am always in a position greater than my rank so I am not used to the other way around.

its possible 97....i've seen an 89B20 here in Okinawa get rated as an 89B10 due to the slot he's holding according to the UMR

You can always work one up and one down. That is the rule.