These lines, Abbreviation, Subsequent Source Citation and Footnote, often appear in source records from gedcoms. None of these items are needed at Wikitree. Their purpose is only for written documents where a source may be repeated this does not happen with a Wikitree profile, all of these lines should be removed.
: Abbreviation: Genealogical Dictionary of Rhode Island by John Osborne Austin
: Subsequent Source Citation Format: Genealogical Dictionary of Rhode Island by John Osborne Austin
::: Name: Footnote
A complete example with a before and after is at Simple Sources.