I propose... a logo! A smallish, universal image(GIF?) that signifies that the site works with old or less-featured browsers. Possible example:



Pretty much means no frames, no fancy Java or Flash, not overmany images. This means remove the frame from that site of yours, it won't display properly on really old browsers.

I'm going to do the same but centered on both old Macs and PCs. We can link to each other.