In brief
A title block can identify the client, drawing author, firm, revision, date, scale and contact details. The labels and layout determine the relationships. Flattened text can lose that context, so an unclear link should remain a candidate.
Separate the labelled fields
A drawing may identify a client, preparer, certifier, surveyor, drawing number, date, scale and revision. A name labelled client should not silently become the architect or landowner. The same caution applies to professional registration and company identifiers.
Check who a channel belongs to
An email near a logo or title block may belong to the firm, a named author or another party. Preserve it as a candidate when that relationship is unclear. A channel can be worth showing before its ownership is resolved.
Check the revision and readable coverage
A flattened text layer may preserve the words but lose their positions and grouping. Scanned drawings may require a different reading route. Missing or partial readable content is a limit on attribution, not proof that a role was absent from the drawing.
Use the result as a connection to investigate
A clearly stated author can support a firm-role observation. Ambiguous layout can support a labelled candidate. Keep both useful, and avoid treating a possible specifier as a confirmed decision-maker or an appointed project participant.