13. Custom Operator Logo

1. Naming and priority

Allowed naming patterns:

1. generic logo: OPERATOR.bmp or OPERATOR.png
2. type-specific logo: OPERATOR-ICAOTYPE.bmp or OPERATOR-ICAOTYPE.png

Runtime priority:

1. type-specific logo is preferred,
2. generic logo is fallback.

2. Validation rules

1. file type must be .bmp or .png,
2. file size limit is 2 MB,
3. required aspect ratio is 17:4,
4. template size is 85x20,
5. if image has valid ratio but larger dimensions, explicit downscale confirmation is required,
6. operator code accepts A-Z, 0-9, @, ., _, +, - (2-40 chars),
7. optional ICAO type accepts A-Z, 0-9 (2-12 chars).

3. Overwrite behavior

1. if target logo already exists and overwrite=false, upload returns conflict,
2. when saving one extension, counterpart extension for same key is removed to keep deterministic lookup.

4. Storage and metadata

1. files are stored in Images/AirlineLogos,
2. upload metadata is tracked in custom-operator-flags.json,
3. after upload/delete, OperatorFlagsList.csv is synchronized,
4. resource service is reloaded immediately.