161: Unrecognized metadata name with link value

You started a line in your document with the squirrel @, which marks a metadata declaration. A metadata declaration assigns a value to a metadata name. In your case, the value is a link. There are certain recognized metadata names and there are ways to declare metadata with arbitrary names. However, your name is neither recognized for use with link values nor uses a syntax for arbitrary names.

Solution

If you meant to use a recognized metadata name, make sure to spell it correctly.

Note that some recognized metadata names expect text as value. If you meant to use such a name, make sure that the value does not begin with an arrow, e.g.:

@ robots: noindex

If you want to use an arbitrary metadata name, you need to prepend the name with a backslash \ like this:

@ \penguin: ->https://en.wikipedia.org/wiki/Penguin

If you did not mean to declare metadata, but want to start the line with a literal @, you can prepend a backslash: \@