The description of the new flag pattern is wrong.

Put the summary of the bug you're having here

What I expected to happen was...:
Described in words such as "pattern of ________", etc.

What actually happened was...:
The description of the new flag pattern is written in non-localized text, such as "block.minecraft.guesser.red" or "block.minecraft.flow.red" (where the "red" is reflected in the color).

It also appears the same way in various languages, including Japanese

Steps to Reproduce:
Attach the newly implemented Banner Pattern to the flag using a loom.