What’s new in babel 25.14

Potentially breaking changes. Extensive testing has been carried out, so I expect issues will be minimal.

This release introduces a major change in the way locales are declared. All available languages can be now loaded as class and package options without the need, in general, for the command \babelprovide or the option provide. For example:

\usepackage[chinese, thai, italian, persian, bidi=default]{babel}

Babel will select the preferred method (ldf or ini) in each case. Remember the number of locales available for pdflatex is more limited (about 170, against about 300 for lualatex and xelatex, with varying degrees of coverage).

Lazy loading is still based always on the ini mechanism, because with ldf files it’s not technically feasible.

Some minor points are still to be fine-tuned, including the manual.

Special cases and known issues with `ldf` styles

The following notes refer to the traditional ldf mechanism (which is not necessarily ‘old’ or ‘discouraged’).

Deprecated names (bahasai, samin, usorbian and a few more) will show a warning. See Locale naming for further info.

`greek`, `monotonicgreek`, `polytonicgreek`, `ancientgreek`

They are recognized, in addition to attributes and modifiers. However, using them at the same time is not supported. The \localename is always greek, but they can be selected with the corresponding names. Actually, internally both greek and the name of the selected variant are mixed, so as a hack the new loader defines two languages with the same definitions but with different names. With pdflatex and xelatex this is very likely not relevant, but with lualatex can be (e.g., transforms).

The correct BCP 47 tags are set only with greek, monotonicgreek, polytonicgreek, and ancientgreek, and not with greek + a modifier or attribute. Note Modern Greek (tags el, el-monoton, el-polyton) is considered a different language than Ancient Greek (tag grc).

The name polutonikogreek is deprecated.

`austrian`, `german`, `swissgerman`

They refer to the old 1901 variant, not the modern one. For the modern 1996 variant, use naustrian and ngerman. For the moment, this legacy behavior is kept, and a warning highlighting it will be shown with german and austrian.

Breaking change. swissgerman is now assigned to the language with tag gsw. For modern Swiss High German (tag de-CH) you can use swisshighgerman (the Unicode CLDR name) and nswissgerman (the legacy name). The \localename is in both cases nswissgerman.

`serbian`, `serbianc`

For the moment, the legacy behavior is kept, so that serbianc is for the Cyrillic script and serbian is for the Latin script. The latter will show a warning highlighting this doesn’t conform the standard naming.

`ethiop`, `amharic`

ethiop is still recognized, but you can also load and select it with amharic, which is the recommended name. The ldf mechanims is used in pdflatex. With Unicode engines, the ini mechanims is used.

arabic, farsi, hebrew, hindi, mongolian, thai

The ldf mechanims is used in pdflatex. With Unicode engines, the ini mechanims is used.

Fixes and other changes

Determining the main language

Breaking change. There was long-standing bug which has remained unnoticed for decades. The documented behavior is the last declared language is set as the main one. That’s true with:

\usepackage[langA,langB,langA]{babel}

But it’s not true with the following, which oddly set langB as the main language:

\documentclass[langA,langB,langA]{article}

It was partly caught by babel, but for another situation (as a warning in the log revealed), namely, a language declared as both class and package option, whose behavior was not well-defined (but preserved for compatibility). The main purpose of the main key was to overcome this inconsistency.

Note languages as class options options don’t mean ‘set it as main language’, but rather ‘pass it as option to all packages’. Admittedly, this can be counter-intuitive, and after all in monolingual documents it’s the main language, too.

After more than 10 years showing a warning, it’s time to normalize the behavior, and now the very last language (considering all class and package options, in this order) is the main language. (What main does is to move it at the end.)

Other fixes

Other fixes:

352: Troubleshooting spanish babel with DocumentMetadata language option.
354: Option ‘polytonicgreek’ fails.
356: \usepackage[austrian]{babel} results in ‘undefined control sequence \l@austrian’.

The option main was ignored after the first \babelprovide for a certain language. This could also solve #351.

Config files

They are deprecated. They can break document portability and there are more modern alternatives to customize the behavior of languages (for example, hooks and packages).

Support for bidi texts with XeTeX

As of this writing, the bidi package, which babel currently relies on for xetex, is unmaintained. It’s strongly recommend switching to a modern workflow based on lualatex, because babel has its own built-in, future-proof mechanism to deal with bidirectional text, providing a more stable and integrated solution.