The string codes
CARGO_LONG CARGO_SHORT CARGO_TINY
take two parameters:
1. Cargo type Id
2. Cargo amount

Some languages try to use plural {P} and referencing these string codes:
{CARGO_LONG} {P "" s}
{P 0 "" s} {CARGO_LONG}

However, this fails, since the amount is the second sub parameter. Correct would be:
{CARGO_LONG} {P 0:1 "" s}
{P 0:1 "" s} {CARGO_LONG}

Solutions to the problem:
A) Eints detects the error. If we find a good error message, translators can fix it by adding ":1" everywhere.
B) Change the order of parameters in OTTD. -> Breaks compatiblity with GS -> no option.
C) Make strgen supply a default sub parameter offset for those string codes.