Thank you all for your input.
Here is the Quebecois Project guideline on dit names: GUIDELINE on how they should be used in Wikitree:
The surname of a child should always be the surname of the father on the baptism, without the dit name (unless illegitimate of course, in which case it will be recorded under the mother's name). If the father is recorded as Jean Doublon dit des Rosiers (not a real name), then only Doublon would be used in the LNAB field of the child . Current last name (CLN) can be used to reflect the Doublon dit des Rosiers IF the child actually used it. BUT, if the only name used on the baptism is a dit name, then that is what is recorded in LNAB field.
The name of the father would be recorded as Doublon in LNAB field, and the name Doublon dit des Rosiers would be entered in CLN box, and also des Rosiers would be entered separately in other last name (OLN) field, for search purposes, and because some records only show the dit name by itself.
Is should look something like this:
- Last name at birth (LNAB): Doublon
- Current last name (CLN): Doublon dit des Rosiers
- Other last name (OLN): des Rosiers
Keep in mind that some children once adult went only by the dit name of the family, in which case it would be entered by itself in CLN field.
*I see profiles being changed without following this guideline. Specifially, the CLN field and the OLN fields are both being populated with des Rosiers (see example above) with no mention of it being a dit name. The existence of a dit name is extremely important for retracing family lines. Please do not remove this key piece of information.