What does X-ray mean?
X-ray is the flag for X. As a single-letter International Code signal, it means: “Stop carrying out your intentions and watch for my signals.” See NGA Publication 102, single-letter signals.
| Property | Description |
|---|---|
| Letter and spelling word | X — X-ray |
| Design | White field with a blue cross. |
| Signal context | The quoted meaning applies to X as a single-letter International Code signal. |
| Hoist-to-fly ratio | No universal manufacturing ratio verified for this record. |
| Cross dimensions | No authoritative numerical cross-width specification verified. |
| Colour specification | Blue and white; no physical colour standard or exact digital colour values verified. |
Construction and evidence limits
The U.S. Coast Guard’s signal-flag chart identifies X as white with a blue cross. This supports identification, but does not establish a dimensioned manufacturing standard for this record.
Official signal meaning, manufactured dimensions and screen artwork are separate evidence categories. No common-manufacture ratio is asserted here. Exact cross widths, fabric colours and tolerances should not be inferred by measuring an illustration. Digital colour values would be screen approximations unless tied to a documented standard; newly drawn geometry would be an editorial reconstruction unless supported by a construction specification.
Code history and present status
The revised International Code was adopted by IMCO’s Fourth Assembly in 1965. NGA’s preface states that the 1969 edition became effective on 1 April 1969. These are Code milestones, not an established first-use date for the X-ray design. See NGA Publication 102, title page and preface.
IMO’s publication overview explains that its later issue contains minor editorial improvements and that both it and the 2005 edition remain valid. X-ray is presented here as a current code flag, rather than a historical-only flag.
Compare Lima
Lima directs the recipient to stop their vessel immediately. X-ray directs the recipient to discontinue their intended action and watch the sender’s signals. The two entries have distinct meanings in NGA’s single-letter signal table.
Sources
- NGA Publication 102: International Code of Signals, 1969 edition, revised 2020 — preface, spelling table and single-letter signals.
- U.S. Coast Guard Proceedings, January–March 1997 — International Marine Signal Flags chart.
- International Maritime Organization — International Code of Signals publication overview and edition status.