Rules for Tapering?

I would say it is not a 'set rule', but more to do with the persons fitness level and ability.

If it were me, I would train up to the weekend before, take a couple days off (Mon,Tue), a swim and easy run Wed, a swim Thurs, and off Friday.

im curious, why dont you bike at all that last week?  i find biking to be the least stressful of the three events.

i also recommend swimming at least 2 times that last week.  i swear my arms feel more tired if i take a break from swimming for even 4 days.  its like im losing some amount of fitness from the down time.

I believe tapering is one of those things that you need to figure out what works best for you.  It is dependent upon a lot of things such as how hard you have been pushing yourself, how long it takes you to heal up from any nagging little aches/pains, how quickly you recover from a standpoint of muscular fatigue but also energy levels.

I run a lot of races so do many mini-tapers that allow a few days to reenergize but do not hinder my overall training plan and goals.  For a few longer, "big" races a year I will taper about a week.  I've tried lounging around with minimal efforts during that week and that generally doesn't work for me.  I get tight and restless with a lethargic feeling come race day.  I'm better to keep intensities fairly high and back way off on the duration of workouts.

I also try to note how I feel the days after light and heavy workout days so I can better gauge how quickly I recover.  For my mini-tapers, I've honed in on a routine that I try to follow each time that is predictable for me.  It's taken some trial and error but if you know you have responded well with a given routine it takes some of the pressure off the unknown.

I always find that sticking to my normal routine is the best. Everything feels off if I rest too much or miss too many workouts and I will tighten up. My advice would be to simply reduce the duration (or distances) of your workouts. Nothing hard, just get out there to make sure you are loose and ready to go. A few strides at race pace never hurt anyone either just to get the pace in your head. Also remember better to get to the start line 10% undertrained and healthy than to get there 1% overtrained and injured.

I also second the "weird things will hurt" bit. Every race a knee or ankle or shoulder will suddenly SCREAM at me like it is injured, and then come race morning I'm fine.

Good Luck! and have fun!