What does # in Java mean?

How do I work with "This AbstractBlock.Properties object can be made using AbstractBlock.Properties#create and it can be customised by calling its methods" because the IDE just gives me a syntax error.

@matrix You create an AbstractBlock.Properties and then call .create on it. It's a notation that's not in the syntax. ex.
https://docs.oracle.com/javase/7/docs/technotes/tools/windows/javadoc.html
{@link package.class#member label}

@apropos Oh, I assumed it's some syntax I'm not aware of because AbstractBlock.Properties doesn't seem to have a create method

@matrix oh, https://stackoverflow.com/questions/66670282/minecraft-forge-block-creation-1-16-5 says it's gone.