diff --git a/docs/languages.md b/docs/languages.md
index 3595dc10..e1514a19 100644
--- a/docs/languages.md
+++ b/docs/languages.md
@@ -35,21 +35,21 @@ The 107 supported languages and accents are:
| `zlw` | `cs` | West Slavic | Czech | |
| `gmq` | `da` | North Germanic | Danish | |
| `gmw` | `nl` | West Germanic | Dutch | |
-| `gmw` | `en-US` | West Germanic | English | American |
+| `gmw` | `en-us` | West Germanic | English | American |
| `gmw` | `en` | West Germanic | English | British |
| `gmw` | `en-029` | West Germanic | English | Caribbean |
-| `gmw` | `en-GB-x-gbclan` | West Germanic | English | Lancastrian |
-| `gmw` | `en-GB-x-rp` | West Germanic | English | Received Pronunciation |
-| `gmw` | `en-GB-scotland` | West Germanic | English | Scottish |
-| `gmw` | `en-GB-x-gbcwmd` | West Germanic | English | West Midlands |
+| `gmw` | `en-gb-x-gbclan` | West Germanic | English | Lancastrian |
+| `gmw` | `en-gb-x-rp` | West Germanic | English | Received Pronunciation |
+| `gmw` | `en-gb-scotland` | West Germanic | English | Scottish |
+| `gmw` | `en-gb-x-gbcwmd` | West Germanic | English | West Midlands |
| `art` | `eo` | Constructed | Esperanto | |
| `urj` | `et` | Uralic | Estonian | |
| `ira` | `fa` | Iranian | Persian | |
-| `ira` | `fa-Latn` | Iranian | Persian\[2\] | |
+| `ira` | `fa-latn` | Iranian | Persian\[2\] | |
| `urj` | `fi` | Uralic | Finnish | |
-| `roa` | `fr-BE` | Romance | French | Belgium |
+| `roa` | `fr-be` | Romance | French | Belgium |
| `roa` | `fr` | Romance | French | France |
-| `roa` | `fr-CH` | Romance | French | Switzerland |
+| `roa` | `fr-ch` | Romance | French | Switzerland |
| `cel` | `ga` | Celtic | Gaelic | Irish |
| `cel` | `gd` | Celtic | Gaelic | Scottish |
| `ccs` | `ka` | South Caucasian | Georgian | |
@@ -92,13 +92,13 @@ The 107 supported languages and accents are:
| `roa` | `pap` | Romance | Papiamento | |
| `art` | `py` | Constructed | Pyash | |
| `zlw` | `pl` | West Slavic | Polish | |
-| `roa` | `pt-BR` | Romance | Portuguese | Brazillian |
+| `roa` | `pt-br` | Romance | Portuguese | Brazillian |
| `myn` | `quc` | Mayan | K'iche' | |
| `roa` | `pt` | Romance | Portuguese | Portugal |
| `inc` | `pa` | Indic | Punjabi | |
| `roa` | `ro` | Romance | Romanian | |
| `zle` | `ru` | East Slavic | Russian | |
-| `zle` | `ru-LV` | East Slavic | Russian | Latvia |
+| `zle` | `ru-lv` | East Slavic | Russian | Latvia |
| `zls` | `sr` | South Slavic | Serbian | |
| `bnt` | `tn` | Bantu | Setswana | |
| `inc` | `sd` | Indic | Sindhi | |
@@ -115,9 +115,9 @@ The 107 supported languages and accents are:
| `dra` | `te` | Dravidian | Telugu | |
| `trk` | `tr` | Turkic | Turkish | |
| `inc` | `ur` | Indic | Urdu | |
-| `aav` | `vi-VN-x-central` | Austroasiatic | Vietnamese | Central Vietnam |
+| `aav` | `vi-vn-x-central` | Austroasiatic | Vietnamese | Central Vietnam |
| `aav` | `vi` | Austroasiatic | Vietnamese | Northern Vietnam |
-| `aav` | `vi-VN-x-south` | Austroasiatic | Vietnamese | Southern Vietnam |
+| `aav` | `vi-vn-x-south` | Austroasiatic | Vietnamese | Southern Vietnam |
| `cel` | `cy` | Celtic | Welsh | |
\[1\] Currently, only fully diacritized Arabic is supported.
diff --git a/espeak-ng-data/lang/ira/fa-Latn b/espeak-ng-data/lang/ira/fa-Latn
index 7a43725b..02c6da6e 100644
--- a/espeak-ng-data/lang/ira/fa-Latn
+++ b/espeak-ng-data/lang/ira/fa-Latn
@@ -1,6 +1,6 @@
name Persian (Pinglish)
// Sometimes, Farsi speakers write Farsi words using English characters, particularly in Chat and SMS (texte messages).), called Pinglish
-language fa-Latn
+language fa-latn
maintainer Shadyar Khodayari
status mature
dictrules 1
diff --git a/espeak-ng-data/lang/zle/ru-LV b/espeak-ng-data/lang/zle/ru-LV
index ec8fa654..fc9541ba 100644
--- a/espeak-ng-data/lang/zle/ru-LV
+++ b/espeak-ng-data/lang/zle/ru-LV
@@ -1,5 +1,5 @@
name Russian (Latvia)
-language ru-LV 2
+language ru-lv 2
maintainer Valdis Vitolins
status testing