RRB signature, 30–49 KB
Recent railway notices capture the photo live and still ask for a signature file. Use running handwriting, not capitals.
The file must sit in a narrow band: at least 30 KB and under 50 KB. Over-compressing fails the minimum.
What usually goes wrong
Crop to the ink. A faint signature will not reach 30 KB.
What this page checks
JPEG, about 35 mm × 20 mm, exported from 276×157 pixels, 30–49 KB. Confirm the CEN notice.