We may be in danger of confusing two things.
On the issue I raised, it would be useful to have a field for alternative registrations which would avoid having to add them as a comment.
The 'French' question is about the confusion between the numeric registration and the alpha numeric code as the code is often more dominant as a fuselage marking than the reg.
Other websites have a field for the code and this if often helpful in tracking down an airframe were it to be included in the search input data.
Do we need two new fields?
Malcolm.