When an element in a patent claims lists one or several alternate components, is there a difference between linking the elements with “and” versus “or”?  Examiners  at the Patent Office may prefer “and” over “or” to avoid indefiniteness, and the recent Patent Trial and Appeal Board ruling in Ex Parte Gross seems to imply the terms can safely be interchanged.

But choose your conjunction carefully – as the plaintiff in Superguide v. DirecTV discovered years ago, the Federal Circuit agrees with Strunk & White in parsing the difference between the two, and a careless use of “and” can make the least bit of difference between winning and losing an infringement suit.