What do the colours of the Qatar flag mean?

Maroon: the bloodshed of the nineteenth-century wars; the shade is said to come from sun-bleached dye. White: peace.

How do you tell the Qatar flag from the Bahrain one?

Bahrain is bright red with five points and a normal 3:5 ratio; Qatar is maroon with nine points and is far longer.

When was the Qatar flag adopted?

The current design dates from 1971, and its official ratio is 11:28.

The flag of Qatar

A maroon field with a white band at the hoist, the two separated by nine white points forming a serrated edge. The longest national flag in proportion.

Ratio 11:28 · current design adopted 1971

At 11:28 it is by a wide margin the longest national flag in the world, more than twice as long as it is tall. The maroon is the other distinguishing feature: the traditional explanation is that Qatar's red dye faded to purple-brown in the Gulf sun until the faded shade was simply adopted. Bahrain's flag is the same serrated design in red with five points, and the two were deliberately differentiated. The nine points were fixed in 1949 and the current proportions in 1971, at independence.

Flags it gets confused with

Flag	How to tell them apart
Bahrain	Bahrain is bright red with five points and a normal 3:5 ratio; Qatar is maroon with nine points and is far longer.

What the colours mean

Flag laws usually specify a Pantone chip, a CMYK mix or just a colour name. Converting any of those to sRGB is lossy, which is why published hex values disagree.

The symbols on it

What	What it stands for
Nine points	Qatar as the ninth member of the "reconciled emirates" of the Gulf, after the 1916 treaty

Ratio: 11:28
Current design adopted: 1971
Colours: maroon, white

Common questions

What does the flag of Qatar look like?: A maroon field with a white band at the hoist, the two separated by nine white points forming a serrated edge. The longest national flag in proportion.
What do the colours of the Qatar flag mean?: Maroon: the bloodshed of the nineteenth-century wars; the shade is said to come from sun-bleached dye. White: peace.
How do you tell the Qatar flag from the Bahrain one?: Bahrain is bright red with five points and a normal 3:5 ratio; Qatar is maroon with nine points and is far longer.
When was the Qatar flag adopted?: The current design dates from 1971, and its official ratio is 11:28.

Qatar Capital, area, population and currency
The flag of Bahrain Routinely mistaken for this one
Every flag with maroon in it

Sources

Wikidata — Wikimedia Foundation (CC0 1.0)

How these figures are compiled and checked