Locale prefs editor behaviour

While adding Preferred Languages in the Locale prefs editor, I've noticed the following: When there are no preferred languages, the language list shows three columns named "Language", "Native Name" and "Charset". As soon as I select a language, the list loses one column and now shows only two, "Language" and "Directory".

What is the reason for this behaviour? And what does "Directory" mean?

@trixie

With OS 4.0, catalogs are no more arranged into directories after the language name for the given language (native name). English names are used instead. The Directory field shows, where the catalogs for the language should be located. That would (typically) be Locale:catalogs/<language> or progdir:catalogs/<language> .

@Thematic

I can understand the internals but why does the GUI behave like that? I mean, why does it show different kinds of information when selecting more languages?

For instance, the editor shows me that the Czech language is associated with the ISO 8859-2 charset. When I select the language, the charset column disappears. Now if I want to select, say, English as another preferred language, why can't I see the charset anymore? Why does "Directory" suddenly become so important that it replaces the charset?

Where catalogs are stored is an OS internal; as a user, I'm not interested (perhaps even don't know what a catalog is and how locale works).

@trixie

Maybe the first selection sets both the language and the charset. But additional selections should set the language only. That second language is fallback if the first one is not available but why would you like to change the charset as well. But I don't know either why that dir info is not displayed always.

@trixie

Quote:AmigaOS 4.x supports configuring several, IIRC up to 10, languages, the catalogs are searched in the order the languages are configured in locale prefs, but only a single default charset which is set by the first language.

For Czech there is only a single charset, but other languages can be used with different charsets, for example there are 3 for Serbian and 2 for a lot of others (ISO-8859-1 or -2 without Euro sign and ISO-8859-15 or -16 with the Euro sign, and a few other differences).
Maybe there should be an ISO-8859-16 version of Czech as well, but I don't know if Czech can be used with that charset or if some chars required for Czech from ISO-8859-2 are missing in ISO-8859-16 and that's the reason why there is no ISO-8859-16 version of it.