Escapable list delimiters
The inline array properties have a separator so that multiple elements can be stored as a simple text, but what if one of those elements needs to have the separator as text? There should be an escaping mechanism. I think the easiest would be to escape separators by doubling them (à la Excel "").
I don't want to use backslashes because the resource's format (like YAML) might already require it to be escaped, and we then have to decide what happens if a backslashes is not followed by the separator.
Edit: Downside to "double-escaping" is if the character appears three times, it's ambiguous which one acts as escaped and which one is a delimiter, respectively under this system, it's impossible to start a string with the delimiter char.