Those 'Span' type sources with the Snnnn come in from Gedcom imports. When you see the #Snnnn in the biography, there 'should' be a Span entry in the Sources section that has the span id='Snnnn' matching the number above and a explanation of the source being used. When there is something like the S2087 in that profile, sometimes people have 'removed' an entry in the Sources or never put the entry in the sources when they are copied from related profiles.
The information you have above is not in that profile that you linked to, only the ref name is seen. You got that description from the spouse profile, I think, since that is where I see it.
If it is missing, I normally look in the Changes Log first, to see if I can find the Span entry with the needed description, then look at Spouse profile, children, or parents. Not finding a description doesn't make sense to keep it since it doesn't have any explanation.
When you do have the description, you can change the 'ref' definition to include the description from the Span entry. In that entry, I would add the 'Descendants of Major John Downing Internet document Hicks' to replace the #S2087. I would also do a google search to see if I could find that source online or in one of our wikitree space pages as a reference point.