perldoc -q here.*?doc

Found in perlfaq4   Why don't my <<HERE documents work?

Short demo

print <<interp, <<'nointerp', <<"inter\"\pol";
  this is $]
interp
  and this is $]
nointerp
  and this is $], semicolon important
  diff quoting rules, you can only escape the "
  not demonstrated are backticks, they also interpolate
inter"\pol

print "the end\n"
__END__
  this is 5.010001
  and this is $]
  and this is 5.010001, semicolon important
  diff quoting rules, you can only escape the "
  not demonstrated are backticks, they also interpolate
the end
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