Trademarks

The best thing is, we don't have to put the little TM symbol next to the trademark, but the trademark people say a writer needs to distinguish what a trademark is by capitalizing the first letter, putting it all in caps, italics or boldface type, or in quotes, then adding the product after the trademark. For example: Apple computers, ZIPLOC resealable bags, "Cheerios" cereal, or Parker (in italics or boldface type) pen. Trademarks should not be pluralized, and it's considered a proper adjective. They should not be used in the possessive form, or as a verb.

From Kay Parkin on TRADEMARKS (from an article found on using trademarks in writing)