Metamask says it only allows tokens with symbol between 0 and 12 chars, but doesn't allow 12 chars

[wmitsuda]

Describe the bug
It is as the bug title says

To Reproduce

1. Add a custom token on Metamask
2. Paste 0x66117f59814DC7f2AaA7A2f90F6ef16F7e2b363D as the token contract address (mainnet)
3. This token symbol has exactly 12 characters
4. The extension complains saying it should be between 0 and 12 characters.
5. If you edit the name and remove 1 character (so it has 11), it accepts the symbol.

Expected behavior
The extension should support 12 characters in the symbol as the error message says.

Screenshots

Browser details (please complete the following information):

• OS: macos Catalina
• Browser: Chrome
• MetaMask Version: 7.7.0.1

[Gudahtt]

The behaviour here does match the error message, though I can see why it would be confusing. It means it should be between 0 and 12 characters exclusive, as in greater than 0 or less than 12. Hence zero not being accepted either.

I think ranges of numbers are generally assumed to be inclusive unless stated otherwise, so this error message should be changed to something easier to understand, e.g. "greater than zero and less than 12 characters"

[wmitsuda]

May I ask why the limit should be 11 and not 12 then? Is there some specification stating these limits?