Hi be. this what you'll have to tranalate for your language file, once finished leave a comment at bug 1638.

/* private */ $wgNamespaceNamesBe = array(
        NS_MEDIA            => 'Media',
        NS_SPECIAL          => 'Special',
        NS_MAIN             => '',
        NS_TALK             => 'Talk',
        NS_USER             => 'User',
        NS_USER_TALK        => 'User_talk',
        NS_PROJECT          => $wgMetaNamespace,
        NS_PROJECT_TALK     => $wgMetaNamespace . '_talk',
        NS_IMAGE            => 'Image',
        NS_IMAGE_TALK       => 'Image_talk',
        NS_MEDIAWIKI        => 'MediaWiki',
        NS_MEDIAWIKI_TALK   => 'MediaWiki_talk',
        NS_TEMPLATE         => 'Template',
        NS_TEMPLATE_TALK    => 'Template_talk',
        NS_HELP             => 'Help',
        NS_HELP_TALK        => 'Help_talk',
        NS_CATEGORY         => 'Category',
        NS_CATEGORY_TALK    => 'Category_talk'
);

/* private */ $wgQuickbarSettingsBe = array(
        'None', 'Fixed left', 'Fixed right', 'Floating left'
);

/* private */ $wgSkinNamesBe = array(
        'standard' => 'Classic',
        'nostalgia' => 'Nostalgia',
        'cologneblue' => 'Cologne Blue',
        'davinci' => 'DaVinci',
        'mono' => 'Mono',
        'monobook' => 'MonoBook',
        'myskin' => 'MySkin',
        'chick' => 'Chick'
);

/* private */ $wgWeekdayNamesBe = array(
        'sunday', 'monday', 'tuesday', 'wednesday', 'thursday',
        'friday', 'saturday'
);


/* private */ $wgMonthNamesBe = array(
        'january', 'february', 'march', 'april', 'may_long', 'june',
        'july', 'august', 'september', 'october', 'november',
        'december'
);
/* private */ $wgMonthNamesGenBe = array(
        'january-gen', 'february-gen', 'march-gen', 'april-gen', 'may-gen', 'june-gen',
        'july-gen', 'august-gen', 'september-gen', 'october-gen', 'november-gen',
        'december-gen'
);

/* private */ $wgMonthAbbreviationsBe = array(
        'jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug',
        'sep', 'oct', 'nov', 'dec'
);

# Note to translators:
#   Please include the English words as synonyms.  This allows people
#   from other wikis to contribute more easily.
#
/* private */ $wgMagicWordsBe = array(
#   ID                                 CASE  SYNONYMS
        MAG_REDIRECT             => array( 0,    '#redirect'              ),
        MAG_NOTOC                => array( 0,    '__NOTOC__'              ),
        MAG_FORCETOC             => array( 0,    '__FORCETOC__'           ),
        MAG_TOC                  => array( 0,    '__TOC__'                ),
        MAG_NOEDITSECTION        => array( 0,    '__NOEDITSECTION__'      ),
        MAG_START                => array( 0,    '__START__'              ),
        MAG_CURRENTMONTH         => array( 1,    'CURRENTMONTH'           ),
        MAG_CURRENTMONTHNAME     => array( 1,    'CURRENTMONTHNAME'       ),
        MAG_CURRENTDAY           => array( 1,    'CURRENTDAY'             ),
        MAG_CURRENTDAYNAME       => array( 1,    'CURRENTDAYNAME'         ),
        MAG_CURRENTYEAR          => array( 1,    'CURRENTYEAR'            ),
        MAG_CURRENTTIME          => array( 1,    'CURRENTTIME'            ),
        MAG_NUMBEROFARTICLES     => array( 1,    'NUMBEROFARTICLES'       ),
        MAG_CURRENTMONTHNAMEGEN  => array( 1,    'CURRENTMONTHNAMEGEN'    ),
        MAG_PAGENAME             => array( 1,    'PAGENAME'               ),
        MAG_PAGENAMEE            => array( 1,    'PAGENAMEE'              ),
        MAG_NAMESPACE            => array( 1,    'NAMESPACE'              ),
        MAG_MSG                  => array( 0,    'MSG:'                   ),
        MAG_SUBST                => array( 0,    'SUBST:'                 ),
        MAG_MSGNW                => array( 0,    'MSGNW:'                 ),
        MAG_END                  => array( 0,    '__END__'                ),
        MAG_IMG_THUMBNAIL        => array( 1,    'thumbnail', 'thumb'     ),
        MAG_IMG_RIGHT            => array( 1,    'right'                  ),
        MAG_IMG_LEFT             => array( 1,    'left'                   ),
        MAG_IMG_NONE             => array( 1,    'none'                   ),
        MAG_IMG_WIDTH            => array( 1,    '$1px'                   ),
        MAG_IMG_CENTER           => array( 1,    'center', 'centre'       ),
        MAG_IMG_FRAMED           => array( 1,    'framed', 'enframed', 'frame' ),
        MAG_INT                  => array( 0,    'INT:'                   ),
        MAG_SITENAME             => array( 1,    'SITENAME'               ),
        MAG_NS                   => array( 0,    'NS:'                    ),
        MAG_LOCALURL             => array( 0,    'LOCALURL:'              ),
        MAG_LOCALURLE            => array( 0,    'LOCALURLE:'             ),
        MAG_SERVER               => array( 0,    'SERVER'                 ),
        MAG_GRAMMAR              => array( 0,    'GRAMMAR:'               ),
        MAG_NOTITLECONVERT       => array( 0,    '__NOTITLECONVERT__', '__NOTC__'),
        MAG_NOCONTENTCONVERT     => array( 0,    '__NOCONTENTCONVERT__', '__NOCC__'),
        MAG_CURRENTWEEK          => array( 1,    'CURRENTWEEK'            ),
        MAG_CURRENTDOW           => array( 1,    'CURRENTDOW'             ),
);

A linktrail will have to be made, this is a regular expression which expands on links, in non-techno babble this means that if you write something like [[foo]]bar in the text it will show up as foobar rathar than foobar, currently this only works for a-z letters in the English alphabet, you'll have to provide a list of letters you want the trail to expand on, for example if you wanted to do something like [[а]]пісаньне and have it show up as апісаньне this would be п,і,с,а,н,ь,н,е.

This should probably be a list of all the letters in your alphabet(s), excluding those in the english alphabet.

If you want the date format can be modified, this is the date format used in signitures (e.g. Ævar Arnfjörð Bjarmason 23:22, 6 .03. 2005 (UTC)), page histories, and so on, the current long date format used is "21:22, 27 .12. 2004", three things can be configured in this regard , time() which returns something like "21:22", date() which returns something like "27 .12. 2004" (used on the headings in recent changes) and then the long date format used on histories, all these functions recive a string like 20050202092742 which can then modified in any conciveable way inside that function, including using the name of the month instead of a number.

See also the image here on is. which shows some examples of how this can be changed.

Date variables
{{CURRENTMONTH}} 12
{{CURRENTMONTHNAME}} сьнежань
{{CURRENTMONTHNAMEGEN}} сьнежня
{{CURRENTDAY}} 25
{{CURRENTDAYNAME}} серада
{{CURRENTYEAR}} 2024
{{CURRENTTIME}} 15:41