>indicates end of the document - from AP Style guide:
Meaning of “###” in a Press Release
In journalism and public relations, three hash signs (###) at the end of a press release — often centered above the boilerplate or under the body copy — is a traditional signal to media that the document is complete www.thehalogroup.com.
Purpose
End-of-document marker: It tells reporters or editors that there is no further copy to come, so they can stop reading and move on to other materials www.thehalogroup.com.
Efficiency: It helps journalists quickly identify the full release without having to scan for other cues like “-30-” or “–END-”.
Tradition: The use of multiple hash signs comes from older media practices, such as telegraphic shorthand (e.g., “XXX” meaning “30” in Roman numerals) and longhand writing where “XXX” marked the end of a story www.thehalogroup.com.
Alternatives
-30-: Common in U.S. journalism, also meaning “the end” www.thehalogroup.com.
–END-: Sometimes used in digital or corporate formats.
###: Preferred by many PR professionals, especially in the U.S. and Canada.
Why It Matters
Using a consistent end-of-document symbol (###, -30-, or –END-) is a sign of professionalism and respect for the media’s time. It signals that your press release is complete and ready for use, improving the chances it will be picked up and published www.thehalogroup.com.
In short: In a press release, “###” is a shorthand, long-standing convention meaning “the end” — a nod to media traditions and a practical way to communicate completeness to journalists.