Whenever using any of these terms in a document (either electronic or otherwise), the first instance of use must include the ™ or ® as required. In the standard trademark boilerplate of your document, you must word the ZEH trademark portion as follows:

"[trademarked name(s) here] are either trademarks or registered trademarks of ZEH Software, Inc. All other marks are the property of their respective owner and/or licensor."