Stage and grade, stage and grade, okay, but what does the and - mean?

At my age and liking to think I keep myself educated as I can about my virus, I find myself with a troubling question regarding my liver biopsy.  It was done in 2003, but I drug it out of my records to take to new doc when I go for my maintenance script.  Will start in September, and by golly, I can hardly wait.

Anyway, I never asked the doc after the orginial biopsy, but what does the + and minus mean?  My numbers look like this....man, is this good reading or what....

Grade...moderate hepatocellular degeneration and necrosis
2-3+/4+

I just have to say, I never necrosis'd in my life.

Stage....Portal and extending fibrosis.... 2+/4+

Severe portal inflammation  (not severe enuff to rate a number)
Lobular inflammation with no regions of hepatocellular necrosis
I guess my lobes are okay.

So, I've always figured I was stage 2, grade 2.  I liked it, easy numbers to remember, not bad numbers either.  But what does the + and minus mean?  More importantly, since it has been three years and some symptoms are getting out of hand, fatigue, etc.