Laniakea
Not of this world
You're new here, & might not know what is standard.
When you claim something, it's best if you support
your claims. It's not the job of others to justify your
claims for you.
Posters often make erroneous claims, so it's impossible
for others to verify those. Your doing your homework
not only saves others time, but you might occasionally
even discover you're wrong.
The standard seems to be to tell someone to post their source, then claim it's not a source once it's posted. I've also been told that it's my job to look up information to back up the claims of others when I'm the one asking for their source.
The standard is a double one.