Temporary register, curious system used during near ten years.
An EC- and three numbers register was asigned to each aircraft before to get the definitive registration.
This interim registration was valid for a maximun of three months.
The B737 in TRA colurs at Boe are not likely KLM a/c in TRA colours but F-GHZD or F-GZHE for TRA france. ZD due for del end of april and ZE due for del end of may