Signals can be sent by flaghoist, signal lamp ("blinker"), flag semaphore, radiotelegraphy, and radiotelephony. The International Code is the most recent evolution of a wide variety of maritime flag signalling systems.

Two sailing ships dressed overall with their signal flags. International maritime signal flags are various flags used to communicate with ships. The principal system of flags and associated codes is the International Code of Signals. [1]

國際信號旗 （英語： international maritime signal flags），或稱 國際 海事 信號旗，是一種船隻間的 旗幟 溝通系統，讓船隻快速清晰地表明自船的意圖。 此系統是 國際信號代碼系統 （英語：International Code of Signals） （International Code of Signals）的一部分。 [1]

Check out the most widely used ICS flag signals practiced by ships as part of a their good seamanship despite today’s technology adoption.

Substitute For the Second Flag. All of our Code of Signal flags are made with 200 denier nylon, sewn throughout with double-stitch seams in approved colors. Finished with strong Canvas Heading with Brass Grommets. Make sure you check out the other nautical flags that we have listed within the store.

The document provides information on letter flags used in the International Code of Signals (ICS), including the phonetic name, design, and meaning of each flag when used as a single flag or with numeric complements.

A set of signal flags consists of twenty-six alphabetical flags, ten numeral pennants, three substitutes, and the answering pennant. Detailed instructions for signaling by flags are given in Chapter 1, Section 5, Pages 8 and 9.

To avoid having to carry multiple flags of the same signal, the ICS uses 3 substitute flags: A substitute flag repeats the one at the indicated position. Boats are not allowed to come alongside. When in distress, signal using these flags: To begin spelling, signal this:

International maritime signal flags refers to various flags used to communicate with ships, associated with the International Codes of Signals (ICS). Single flags can also have specific meanings (urgent, important or common messages) other that representing a letter.

Although the flags of the International Code of Signals can be used to spell out words in full, their normal and more efficient mode of operations is in basic one, two, or three flag combinations, with complementary flags or pennants added to add precision to a message.