To represent various underline types (which QD itself doesn't understand) an extended (i.e., text engine-specific) attribute is applied. If present this tells WASTE which underline style to draw.
So, when underlined text in RTF is transferred into SC field, a QD's flag of "underline" style inevitably puts up.
If I want to transfer dotted underline in RTF into SC field as dotted underscore without QD's underline, I must cancel the QD's underline using "post-editing." I understand.
§ Post-editing: one of my own nomenclatures. Editing contents of a field using SuperTalk after RTF data is transferred into the field. antonym: pre-editing.
§ Pre-editing: one of my own nomenclatures. Editing rtf data using SuperTalk immediately before the data is transferred into a SC field.