HTML Validator

I have run into a minor issue where I am using ASCII characters, as presentation text - between the tags - that display in IE but not in NS; This is a standards error, and while I have tried to correct it by using character symbols it won't display in Netscape: it is this or else I diminish the IE presentation to get standard.

I want to be standard, but I expect to serve everyone well; Until recently I have forked NS/MS; my websites seldom support the 'back' button, though out of necessity they support alternative navigation options, some far more complex. What would you suggest, that I diminish my content or conform?