sentences:  Thus new MMCs are only produced for original and renewals; raises in grade, removal or limitations, or addition of endorsements do not require a new credential.The mariner's reference number and the MMC's serial number are printed on the bottom of every page containing endorsement information and on all stickers issued to be added.The endorsement pages are overprinted with a transparent plastic 'watermark' with the words 'Merchant Mariner Credential' and the seal of the United States.