Czech license plate: Export (documented since 2001)

Format, years and the law

Format: 9L9 9999, for example 2L4 3718 (L is any letter, 9 any digit)
The format above follows the issuing rules: a registration that fits it is one this series could have issued.
Years issued: Documented since 2001; the format is likely older than the first year documented. Still issued.
Vehicle class: Export: plates for vehicles leaving the jurisdiction permanently. Issued for car, van, truck, bus, motorcycle, and trailer.
Colours: Characters #000000 Background #FFFFFF
Size: 520 × 110 mm · every country's size
About this plate: THE EXPORT MARK, an ordinary Czech mark on a plate carrying a red validity field at the right-hand end, valid at most three months. Note the difference in wording between the two regulations, which is a real narrowing: 2001 said "odhlášená k trvalému vývozu do zahraničí" (deregistered for PERMANENT export), 2014 says simply "vyvezená do jiného státu".
How long it is valid: maximum 3 months from assignment, § 29 odst. 2 písm. d): 'Platnost se stanovuje maximálně na 3 měsíce od jejího přidělení'

The series id is cz-export. The API returns its format, validation, colours and designs with the rest of Czechia's series:

curl -s https://vehiclesdb.com/api/v1/plates/cz \
  -H "Authorization: Bearer $VEHICLESDB_API_KEY" \
  | jq '.series[] | select(.id == "cz-export")'