POSIX gettext(): behaviour if iconv() produces a replacement character

[Bruno Haible]

https://posix.rhansen.org/p/gettext_draft
Line 350

"If a significant proportion of the converted message string would consist
 of characters resulting from non-identical conversions ..."

The term "significant proportion" is undefined.

Suggestion: Change
"If a significant proportion of the converted message string would consist
 of characters resulting from non-identical conversions that do not provide
 any information about the character they were converted from (for example,
 if the converted message string would be mostly <question-mark> or
 <replacement-character> characters)"
to
"If at least one of the non-identical conversions produces a fallback
 character (such as <question-mark> or <replacement-character>, depending
 on implementation)"

Rationale: There is no point in forcing gettext() to accept the converted
string when it has low quality.