As usual, can you please give a source?

• Both codes unsourced, but French Wikipedia says that the F67 is only for the Dokker Van, the code of the standard Dokker being K67;
• The F67 code is also used by L'Argus for the Dokker Van (fr) , while the standard Dokker and the Dokker Stepway use indeed the K67 model code (both codes unsourced too, but L'Argus is a well known auto magazine/site founded in 1927).

So it's certainly more accurate to set the model code as:
• F67 for all Dokker Van and Dokker Express (but this code seems to be already present for the Express. I'll add the code manually for the Van models);
• K67 for the rest of the Dokker ("NOT IN" research is not possible in the search page, sorry ).