I agree that Sources Style Guide (SSG) is misleading but according to pre-1700 self certification questionnaire:
- The Style Guide ultimately decides the proper style and format for a WikiTree profile's data fields, biography, and sources.
SSG is crystal clear that a source is a source list item, a bibliography item or a work's cited item.
Use of See also header designation 'under the line' is a poorly thought-out misnomer. For example,Wikipedia differentiates between notation-only Notes, References, Bibliography and See also headers. And so should WT.
WT should call a spade a spade and allow Source list, Bibiliography or Works cites to be used interchangeable instead of See also.
The convention described in Best Answer above is good convention applicable for most WT profiles. But for more complex profiles, SSG should optionally be as currently described in SSG such that any given Bibliography item is interrelated with at least one inline citation reference.