diff --git a/docs/phonemes.md b/docs/phonemes.md
index e1a7e8d2..be90af33 100644
--- a/docs/phonemes.md
+++ b/docs/phonemes.md
@@ -1,13 +1,12 @@
# Phonemes
+- [Phoneme Transcriptions](#phoneme-transcriptions)
- [Consonants](#consonants)
- - [Other Symbols](#other-symbols)
- - [Gemination](#gemination)
- [Manner of Articulation](#manner-of-articulation)
- [Place of Articulation](#place-of-articulation)
- [Voice](#voice)
+ - [Gemination](#gemination)
- [Vowels](#vowels)
- - [Other Symbols](#other-symbols-1)
- [Rounding](#rounding)
- [Height](#height)
- [Backness](#backness)
@@ -22,12 +21,7 @@
- [Tongue Root](#tongue-root)
- [Fortis and Lenis](#fortis-and-lenis)
- [Suprasegmentals](#suprasegmentals)
- - [Stress](#stress)
- [Length](#length)
- - [Rhythm](#rhythm)
- - [Intonation](#intonation)
- - [Tone Stepping](#tone-stepping)
- - [Tones](#tones)
- [References](#references)
----------
@@ -48,73 +42,41 @@ Instead, it is designed to be a transcription guide for authors of espeak-ng
languages and voices on how to specify phonemes so that the IPA and feature
transcriptions are consistent.
+## Phoneme Transcriptions
+
+The following table lists phonetic transcription schemes based on the
+International Phonetic Alphabet (IPA):
+
+| BCP47 Variant Name | Transcription Name | Encoding |
+|---------------------------------|---------------------------------------|----------|
+| foncxs | Conlang X-SAMPA (CXS) | ASCII |
+| [fonipa](phonemes/fonipa.md) | International Phonetic Alphabet (IPA) | Unicode |
+| fonkirsh | Kirshenbaum (ASCII-IPA) | ASCII |
+| fonxsampa | X-SAMPA | ASCII |
+
+__NOTE:__ The `foncxs` and `fonkirsh` variant names are not defined in the
+[IANA language subtag registry](https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry).
+Instead, they are private use extensions defined in the
+[bcp47-data](https://raw.githubusercontent.com/espeak-ng/bcp47-data/master/bcp47-extensions)
+project.
+
## Consonants
-| | `blb` | | `lbd` | | `dnt` | | `alv` | | `pla` | | `rfx` | | `alp` | | `pal` | | `vel` | | `uvl` | | `phr` | | `glt` | |
-|-----------------------------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|
-| | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` |
-| `nas` | m̥ | m | | ɱ | | | n̥ | n | | | ɳ̊ | ɳ | ɲ̟̊ | ɲ̟ | ɲ̊ | ɲ | ŋ̊ | ŋ | ɴ̥ | ɴ | | | | |
-| `stp` | p | b | p̪ | b̪ | t̪ | d̪ | t | d | | | ʈ | ɖ | | | c | ɟ | k | ɡ | q | ɢ | ʡ | | ʔ | |
-| `sib` `afr` | | | | | | | t͡s | d͡z | t͡ʃ | d͡ʒ | ʈ͡ʂ | ɖ͡ʐ | t͡ɕ | d͡ʑ | | | | | | | | | | |
-| `afr` | p͡ɸ | b͡β | p̪͡f | b̪͡v | t͡θ | d͡ð | | | | | | | | | c͡ç | ɟ͡ʝ | k͡x | ɡ͡ɣ | q͡χ | ɢ͡ʁ | ʡ͡ħ | ʡ͡ʕ | ʔ͡h | |
-| `lat` `afr` | | | | | | | t͡ɬ | d͡ɮ | | | ʈ͡ɭ̊˔ | | | | c͡ʎ̥˔ | | k͡ʟ̝̊ | ɡ͡ʟ̝ | | | | | | |
-| `sib` `frc` | | | | | | | s | z | ʃ | ʒ | ʂ | ʐ | ɕ | ʑ | | | | | | | | | | |
-| `frc` | ɸ | β | f | v | θ | ð | | | | | | | | | ç | ʝ | x | ɣ | χ | ʁ | ħ | ʕ | h | ɦ |
-| `lat` `frc` | | | | | | | ɬ | ɮ | | | ɭ̊˔ | | | | ʎ̥˔ | ʎ̝ | ʟ̝̊ | ʟ̝ | | | | | | |
-| `apr` | | | ʋ̥ | ʋ | | | ɹ̥ | ɹ | | | ɻ̊ | ɻ | | | j̊ | j | ɰ̊ | ɰ | | | | | | |
-| `lat` `apr` | | | | | | | l̥ | l | | | ɭ̊ | ɭ | | | ʎ̥ | ʎ | ʟ̥ | ʟ | | ʟ̠ | | | | |
-| `flp` | | ⱱ̟ | | ⱱ | | | ɾ̥ | ɾ | | | ɽ̊ | ɽ | | | | | | | | ɢ̆ | | ʡ̮ | | |
-| `lat` `flp` | | | | | | | | ɺ | | | | ɭ̆ | | | | ʎ̮ | | ʟ̆ | | | | | | |
-| `trl` | | ʙ | | | | | r̥ | r | | | ɽ͡r̥ | ɽ͡r | | | | | | | ʀ̥ | ʀ | ʜ | ʢ | | |
-| `clk` | ʘ | | | | ǀ | | ǃ | | | | | | ǂ | | | | | | | | | | | |
-| `lat` `clk` | | | | | | | ǁ | | | | | | | | | | | | | | | | | |
-| `imp` | | ɓ | | | | | | ɗ | | | | | | | | ʄ | | ɠ | | ʛ | | | | |
-| `ejc` | | | | | | | tʼ | | | | ʈʼ | | | | cʼ | | kʼ | | qʼ | | ʡʼ | | | |
-| `ejc` `frc` | pʼ | | | | θʼ | | sʼ | | ʃʼ | | ʂʼ | | | | | | xʼ | | χʼ | | | | | |
-| `lat` `ejc` `frc` | fʼ | | | | | | ɬʼ | | | | | | | | | | | | | | | | | |
-
-### Other Symbols
-
-| | `bld` | | `alv` | | `pla` | | `pal` | | `lbv` | | `vel` | |
-|-----------------------------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|
-| | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` |
-| `nas` | | | | | | | | | | ŋ͡m | | |
-| `stp` | | | | | | | | | k͡p | ɡ͡b | | |
-| `afr` | p͡f | b͡v | | | | | | | | | | |
-| `vzd` `frc` | | | | | ɧ | | | | | | | |
-| `ptr` `apr` | | | | | | | | ɥ | | | ʍ | w |
-| `fzd` `lat` `apr` | | | | ɫ | | | | | | | | |
-
-### Gemination
-
-Gemination is found in several languages including Italian and Japanese.
-It is also present in the suprasegmental phonology between words such as
-"lamppost" and "evenness".
-
-Some linguists use the [long](#length) suprasegmental for geminate consonants.
-The eSpeak NG convention is to use consonant length for [phonation](#phonation)
-when consonant length is distinct without gemination occurring.
-
-The way gemination is represented in eSpeak NG is to duplicate the phonemes,
-with the first phoneme using the `unx` feature. For example, n̚.n for a
-geminated n. This describes how with the `stp` and `nas` consonants, the
-mouth remains closed (`unx`) for the first of the geminated consonants.
-
### Manner of Articulation
-| Feature | Symbol | Name |
-|-----------|--------|----------------|
-| `nas` | | nasal |
-| `stp` | | plosive (stop) |
-| `afr` | | affricate |
-| `frc` | | fricative |
-| `flp` | | tap/flap |
-| `trl` | | trill |
-| `apr` | | approximant |
-| `clk` | | click |
-| `ejc` | | ejective |
-| `imp` | ◌ʼ | implosive |
-| `vwl` | | vowel |
+| Feature | Name |
+|-----------|----------------|
+| `nas` | nasal |
+| `stp` | plosive (stop) |
+| `afr` | affricate |
+| `frc` | fricative |
+| `flp` | tap/flap |
+| `trl` | trill |
+| `apr` | approximant |
+| `clk` | click |
+| `ejc` | ejective |
+| `imp` | implosive |
+| `vwl` | vowel |
The `vwl` phonemes are described using vowel height and backness features,
while consonants (the other manners of articulation) are described using
@@ -148,7 +110,7 @@ features:
| `glt` | glottal |
The `bld` place of articulation is used for `afr` consonants that have a `blb`
-onset and a `lbd` release, e.g. in the German p͡f consonant.
+onset and a `lbd` release, e.g. in the German `[p͡f]` consonant.
__NOTE:__ The IPA charts make a distinction between pharyngeal and epiglottal
consonants, but Wikipedia does not. This model uses the Wikipedia descriptions.
@@ -160,30 +122,23 @@ consonants, but Wikipedia does not. This model uses the Wikipedia descriptions.
| `vls` | voiceless |
| `vcd` | voiced |
+### Gemination
+
+Gemination is found in several languages including Italian and Japanese.
+It is also present in the suprasegmental phonology between words such as
+"lamppost" and "evenness".
+
+Some linguists use the [long](#length) suprasegmental for geminate consonants.
+The eSpeak NG convention is to use consonant length for [phonation](#phonation)
+when consonant length is distinct without gemination occurring.
+
+The way gemination is represented in eSpeak NG is to duplicate the phonemes,
+with the first phoneme using the `unx` feature. For example, `[n̚.n]` for a
+geminated `[n]`. This describes how with the `stp` and `nas` consonants, the
+mouth remains closed (`unx`) for the first of the geminated consonants.
+
## Vowels
-| | `fnt` | | `cnt` | | `bck` | |
-|--------|-------|-------|-------|-------|-------|-------|
-| | `unr` | `rnd` | `unr` | `rnd` | `unr` | `rnd` |
-| `hgh` | i | y | ɨ | ʉ | ɯ | u |
-| `smh` | ɪ | ʏ | | | | ʊ |
-| `umd` | e | ø | ɘ | ɵ | ɤ | o |
-| `mid` | | | ə | | | |
-| `lmd` | ɛ | œ | ɜ | ɞ | ʌ | ɔ |
-| `sml` | æ | | ɐ | | | |
-| `low` | a | ɶ | | | ɑ | ɒ |
-
-__NOTE:__ The `smh` vowels are more `cnt` than the other vowels. However, this
-distinction is not needed to classify these vowels, so is not included in the
-above table.
-
-### Other Symbols
-
-| Symbol | Features |
-|--------|-------------------------------|
-| ɚ | `unr` `mid` `cnt` `rzd` `vwl` |
-| ɝ | `unr` `lmd` `cnt` `rzd` `vwl` |
-
### Height
| Feature | Name |
@@ -204,6 +159,10 @@ above table.
| `cnt` | center |
| `bck` | back |
+__NOTE:__ The `smh` vowels (`[ɪ]`, `[ʏ]`, `[ʊ]`) are more `cnt` than the
+other vowels. However, this distinction is not needed to classify these
+vowels, so is not included in the phoneme model described in this document.
+
### Rounding
| Feature | Name |
@@ -215,19 +174,19 @@ above table.
### Articulation
-| Feature | Symbol | Name |
-|---------|--------|-----------------|
-| `lgl` | ◌̼ | linguolabial |
-| `idt` | ◌̪͆ | interdental |
-| | ◌̪ | dental |
-| `apc` | ◌̺ | apical |
-| `lmn` | ◌̻ | laminal |
-| | ◌̟ | advanced |
-| | ◌̠ | retracted |
-| | ◌̈ | centralized |
-| | ◌̽ | mid-centralized |
-| | ◌̝ | raised |
-| | ◌̞ | lowered |
+| Feature | Name |
+|---------|-----------------|
+| `lgl` | linguolabial |
+| `idt` | interdental |
+| | dental |
+| `apc` | apical |
+| `lmn` | laminal |
+| | advanced |
+| | retracted |
+| | centralized |
+| | mid-centralized |
+| | raised |
+| | lowered |
The articulations that do not have a corresponding feature name are recorded
using the features of their new location in the consonant or vowel charts, not
@@ -235,85 +194,77 @@ using the features of the base phoneme.
### Air Flow
-| Feature | Symbol | Name |
-|---------|--------|------------|
-| `egs` | ↑ | egressive |
-| `igs` | ↓ | ingressive |
-
-The ↑ and ↓ symbols are from the extended IPA\[7\].
-They only need to be used when the air flow is different to the base IPA
-phoneme (e.g. using ↓ on pulmonic consonants).
+| Feature | Name |
+|---------|------------|
+| `egs` | egressive |
+| `igs` | ingressive |
### Phonation
-| Feature | Symbol | Name |
-|---------|--------|-----------------|
-| `brv` | ◌̤ | breathy voice |
-| `slv` | ◌̥ | slack voice |
-| `stv` | ◌̬ | stiff voice |
-| `crv` | ◌̰ | creaky voice |
-| `glc` | ʔ͡◌ | glottal closure |
-
-The IPA ◌̥ diacritic is also used to fill the `vls` spaces in the IPA consonant
-charts. Thus, when ◌̥ is used with a `vcd` consonant that does not have an
-equivalent `vls` consonant, the resulting consonant is `vls`, not `slv`.
+| Feature | Name |
+|---------|-----------------|
+| `brv` | breathy voice |
+| `slv` | slack voice |
+| `stv` | stiff voice |
+| `crv` | creaky voice |
+| `glc` | glottal closure |
### Rounding and Labialization
-| Feature | Symbol | Name |
-|---------|--------|------------|
-| `ptr` | ◌ʷ, ◌ᶣ | protruded |
-| `cmp` | ◌ᵝ | compressed |
+| Feature | Name |
+|---------|------------|
+| `ptr` | protruded |
+| `cmp` | compressed |
The degree of rounding/labialization can be specified using the following
features:
-| Feature | Symbol | Name |
-|---------|--------|--------------|
-| `mrd` | ◌̹ | more rounded |
-| `lrd` | ◌̜ | less rounded |
+| Feature | Name |
+|---------|--------------|
+| `mrd` | more rounded |
+| `lrd` | less rounded |
### Syllabicity
-| Feature | Symbol | Name |
-|---------|--------|-----------------|
-| `syl` | ◌̩ | syllabic |
-| `nsy` | ◌̯ | non-syllabic |
+| Feature | Name |
+|---------|-----------------|
+| `syl` | syllabic |
+| `nsy` | non-syllabic |
### Consonant Release
-| Feature | Symbol | Name |
-|---------|--------|---------------------------------|
-| `asp` | ◌ʰ | aspirated |
-| `nrs` | ◌ⁿ | nasal release |
-| `lrs` | ◌ˡ | lateral release |
-| `unx` | ◌̚ | no audible release (unexploded) |
+| Feature | Name |
+|---------|---------------------------------|
+| `asp` | aspirated |
+| `nrs` | nasal release |
+| `lrs` | lateral release |
+| `unx` | no audible release (unexploded) |
### Co-articulation
-| Feature | Symbol | Name |
-|---------|--------|----------------|
-| `pzd` | ◌ʲ | palatalized |
-| `vzd` | ◌ˠ | velarized |
-| `fzd` | ◌ˤ | pharyngealized |
-| `nzd` | ◌̃ | nasalized |
-| `rzd` | ◌˞ | rhoticized |
+| Feature | Name |
+|---------|----------------|
+| `pzd` | palatalized |
+| `vzd` | velarized |
+| `fzd` | pharyngealized |
+| `nzd` | nasalized |
+| `rzd` | rhoticized |
### Tongue Root
The tongue root position can be specified using the following features:
-| Feature | Symbol | Name |
-|---------|--------|-----------------------|
-| `atr` | ◌̘ | advanced tongue root |
-| `rtr` | ◌̙ | retracted tongue root |
+| Feature | Name |
+|---------|-----------------------|
+| `atr` | advanced tongue root |
+| `rtr` | retracted tongue root |
### Fortis and Lenis
-| Feature |Symbol | Name |
-|---------|-------|--------|
-| `fts` | ◌͈ | fortis |
-| `lns` | ◌͉ | lenis |
+| Feature | Name |
+|---------|--------|
+| `fts` | fortis |
+| `lns` | lenis |
The extended IPA\[7\] ◌͈ and ◌͉ diacritics
are used to specify lesser (`lns`) and greater (`fts`) oral pressure than
@@ -328,12 +279,12 @@ the [length](#length) suprasegmentals are used instead.
### Length
-| Feature | Symbol | Name |
-|---------|--------|-----------------|
-| `est` | ◌̆ | extra short |
-| `hlg` | ◌ˑ | half-long |
-| `lng` | ◌ː | long |
-| `elg` | ◌ːː | extra long |
+| Feature | Name |
+|---------|-----------------|
+| `est` | extra short |
+| `hlg` | half-long |
+| `lng` | long |
+| `elg` | extra long |
## References
diff --git a/docs/phonemes/fonipa.md b/docs/phonemes/fonipa.md
new file mode 100644
index 00000000..0910f5df
--- /dev/null
+++ b/docs/phonemes/fonipa.md
@@ -0,0 +1,225 @@
+# International Phonetic Alphabet (IPA) Phonemes
+
+- [Consonants](#consonants)
+ - [Other Symbols](#other-symbols)
+- [Vowels](#vowels)
+ - [Other Symbols](#other-symbols-1)
+- [Diacritics](#diacritics)
+ - [Articulation](#articulation)
+ - [Air Flow](#air-flow)
+ - [Phonation](#phonation)
+ - [Rounding and Labialization](#rounding-and-labialization)
+ - [Syllabicity](#syllabicity)
+ - [Consonant Release](#consonant-release)
+ - [Co-articulation](#co-articulation)
+ - [Tongue Root](#tongue-root)
+ - [Fortis and Lenis](#fortis-and-lenis)
+- [Suprasegmentals](#suprasegmentals)
+ - [Length](#length)
+- [References](#references)
+
+----------
+
+This document describes the International Phonetic Alphabet (IPA) transcription
+scheme using [phoneme features](../phonemes.md) based on those described by
+Evan Kirshenbaum \[1\], \[2\].
+
+## Consonants
+
+| | `blb` | | `lbd` | | `dnt` | | `alv` | | `pla` | | `rfx` | | `alp` | | `pal` | | `vel` | | `uvl` | | `phr` | | `glt` | |
+|-----------------------------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|
+| | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` |
+| `nas` | m̥ | m | | ɱ | | | n̥ | n | | | ɳ̊ | ɳ | ɲ̟̊ | ɲ̟ | ɲ̊ | ɲ | ŋ̊ | ŋ | ɴ̥ | ɴ | | | | |
+| `stp` | p | b | p̪ | b̪ | t̪ | d̪ | t | d | | | ʈ | ɖ | | | c | ɟ | k | ɡ | q | ɢ | ʡ | | ʔ | |
+| `sib` `afr` | | | | | | | t͡s | d͡z | t͡ʃ | d͡ʒ | ʈ͡ʂ | ɖ͡ʐ | t͡ɕ | d͡ʑ | | | | | | | | | | |
+| `afr` | p͡ɸ | b͡β | p̪͡f | b̪͡v | t͡θ | d͡ð | | | | | | | | | c͡ç | ɟ͡ʝ | k͡x | ɡ͡ɣ | q͡χ | ɢ͡ʁ | ʡ͡ħ | ʡ͡ʕ | ʔ͡h | |
+| `lat` `afr` | | | | | | | t͡ɬ | d͡ɮ | | | ʈ͡ɭ̊˔ | | | | c͡ʎ̥˔ | | k͡ʟ̝̊ | ɡ͡ʟ̝ | | | | | | |
+| `sib` `frc` | | | | | | | s | z | ʃ | ʒ | ʂ | ʐ | ɕ | ʑ | | | | | | | | | | |
+| `frc` | ɸ | β | f | v | θ | ð | | | | | | | | | ç | ʝ | x | ɣ | χ | ʁ | ħ | ʕ | h | ɦ |
+| `lat` `frc` | | | | | | | ɬ | ɮ | | | ɭ̊˔ | | | | ʎ̥˔ | ʎ̝ | ʟ̝̊ | ʟ̝ | | | | | | |
+| `apr` | | | ʋ̥ | ʋ | | | ɹ̥ | ɹ | | | ɻ̊ | ɻ | | | j̊ | j | ɰ̊ | ɰ | | | | | | |
+| `lat` `apr` | | | | | | | l̥ | l | | | ɭ̊ | ɭ | | | ʎ̥ | ʎ | ʟ̥ | ʟ | | ʟ̠ | | | | |
+| `flp` | | ⱱ̟ | | ⱱ | | | ɾ̥ | ɾ | | | ɽ̊ | ɽ | | | | | | | | ɢ̆ | | ʡ̮ | | |
+| `lat` `flp` | | | | | | | | ɺ | | | | ɭ̆ | | | | ʎ̮ | | ʟ̆ | | | | | | |
+| `trl` | | ʙ | | | | | r̥ | r | | | ɽ͡r̥ | ɽ͡r | | | | | | | ʀ̥ | ʀ | ʜ | ʢ | | |
+| `clk` | ʘ | | | | ǀ | | ǃ | | | | | | ǂ | | | | | | | | | | | |
+| `lat` `clk` | | | | | | | ǁ | | | | | | | | | | | | | | | | | |
+| `imp` | | ɓ | | | | | | ɗ | | | | | | | | ʄ | | ɠ | | ʛ | | | | |
+| `ejc` | | | | | | | tʼ | | | | ʈʼ | | | | cʼ | | kʼ | | qʼ | | ʡʼ | | | |
+| `ejc` `frc` | pʼ | | | | θʼ | | sʼ | | ʃʼ | | ʂʼ | | | | | | xʼ | | χʼ | | | | | |
+| `lat` `ejc` `frc` | fʼ | | | | | | ɬʼ | | | | | | | | | | | | | | | | | |
+
+### Other Symbols
+
+| | `bld` | | `alv` | | `pla` | | `pal` | | `lbv` | | `vel` | |
+|-----------------------------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|-------|
+| | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` | `vls` | `vcd` |
+| `nas` | | | | | | | | | | ŋ͡m | | |
+| `stp` | | | | | | | | | k͡p | ɡ͡b | | |
+| `afr` | p͡f | b͡v | | | | | | | | | | |
+| `vzd` `frc` | | | | | ɧ | | | | | | | |
+| `ptr` `apr` | | | | | | | | ɥ | | | ʍ | w |
+| `fzd` `lat` `apr` | | | | ɫ | | | | | | | | |
+
+### Manner of Articulation
+
+| Feature | Symbol | Name |
+|-----------|--------|----------------|
+| `imp` | ◌ʼ | implosive |
+
+## Vowels
+
+| | `fnt` | | `cnt` | | `bck` | |
+|--------|-------|-------|-------|-------|-------|-------|
+| | `unr` | `rnd` | `unr` | `rnd` | `unr` | `rnd` |
+| `hgh` | i | y | ɨ | ʉ | ɯ | u |
+| `smh` | ɪ | ʏ | | | | ʊ |
+| `umd` | e | ø | ɘ | ɵ | ɤ | o |
+| `mid` | | | ə | | | |
+| `lmd` | ɛ | œ | ɜ | ɞ | ʌ | ɔ |
+| `sml` | æ | | ɐ | | | |
+| `low` | a | ɶ | | | ɑ | ɒ |
+
+__NOTE:__ The `smh` vowels are more `cnt` than the other vowels. However, this
+distinction is not needed to classify these vowels, so is not included in the
+above table.
+
+### Other Symbols
+
+| Symbol | Features |
+|--------|-------------------------------|
+| ɚ | `unr` `mid` `cnt` `rzd` `vwl` |
+| ɝ | `unr` `lmd` `cnt` `rzd` `vwl` |
+
+## Diacritics
+
+### Articulation
+
+| Feature | Symbol | Name |
+|---------|--------|-----------------|
+| `lgl` | ◌̼ | linguolabial |
+| `idt` | ◌̪͆ | interdental |
+| | ◌̪ | dental |
+| `apc` | ◌̺ | apical |
+| `lmn` | ◌̻ | laminal |
+| | ◌̟ | advanced |
+| | ◌̠ | retracted |
+| | ◌̈ | centralized |
+| | ◌̽ | mid-centralized |
+| | ◌̝ | raised |
+| | ◌̞ | lowered |
+
+The articulations that do not have a corresponding feature name are recorded
+using the features of their new location in the consonant or vowel charts, not
+using the features of the base phoneme.
+
+### Air Flow
+
+| Feature | Symbol | Name |
+|---------|--------|------------|
+| `egs` | ↑ | egressive |
+| `igs` | ↓ | ingressive |
+
+The ↑ and ↓ symbols are from the extended IPA\[5\].
+They only need to be used when the air flow is different to the base IPA
+phoneme (e.g. using ↓ on pulmonic consonants).
+
+### Phonation
+
+| Feature | Symbol | Name |
+|---------|--------|-----------------|
+| `brv` | ◌̤ | breathy voice |
+| `slv` | ◌̥ | slack voice |
+| `stv` | ◌̬ | stiff voice |
+| `crv` | ◌̰ | creaky voice |
+| `glc` | ʔ͡◌ | glottal closure |
+
+The IPA ◌̥ diacritic is also used to fill the `vls` spaces in the IPA consonant
+charts. Thus, when ◌̥ is used with a `vcd` consonant that does not have an
+equivalent `vls` consonant, the resulting consonant is `vls`, not `slv`.
+
+### Rounding and Labialization
+
+| Feature | Symbol | Name |
+|---------|--------|------------|
+| `ptr` | ◌ʷ, ◌ᶣ | protruded |
+| `cmp` | ◌ᵝ | compressed |
+
+The degree of rounding/labialization can be specified using the following
+features:
+
+| Feature | Symbol | Name |
+|---------|--------|--------------|
+| `mrd` | ◌̹ | more rounded |
+| `lrd` | ◌̜ | less rounded |
+
+### Syllabicity
+
+| Feature | Symbol | Name |
+|---------|--------|-----------------|
+| `syl` | ◌̩ | syllabic |
+| `nsy` | ◌̯ | non-syllabic |
+
+### Consonant Release
+
+| Feature | Symbol | Name |
+|---------|--------|---------------------------------|
+| `asp` | ◌ʰ | aspirated |
+| `nrs` | ◌ⁿ | nasal release |
+| `lrs` | ◌ˡ | lateral release |
+| `unx` | ◌̚ | no audible release (unexploded) |
+
+### Co-articulation
+
+| Feature | Symbol | Name |
+|---------|--------|----------------|
+| `pzd` | ◌ʲ | palatalized |
+| `vzd` | ◌ˠ | velarized |
+| `fzd` | ◌ˤ | pharyngealized |
+| `nzd` | ◌̃ | nasalized |
+| `rzd` | ◌˞ | rhoticized |
+
+### Tongue Root
+
+| Feature | Symbol | Name |
+|---------|--------|-----------------------|
+| `atr` | ◌̘ | advanced tongue root |
+| `rtr` | ◌̙ | retracted tongue root |
+
+### Fortis and Lenis
+
+| Feature | Symbol | Name |
+|---------|--------|--------|
+| `fts` | ◌͈ | fortis |
+| `lns` | ◌͉ | lenis |
+
+## Suprasegmentals
+
+### Length
+
+| Feature | Symbol | Name |
+|---------|--------|-----------------|
+| `est` | ◌̆ | extra short |
+| `hlg` | ◌ˑ | half-long |
+| `lng` | ◌ː | long |
+| `elg` | ◌ːː | extra long |
+
+## References
+
+1. Kirshenbaum, Evan,
+ [Representing IPA phonetics in ASCII](http://www.kirshenbaum.net/IPA/faq.html) (HTML). 1993.
+
+2. Kirshenbaum, Evan,
+ [Representing IPA phonetics in ASCII](http://www.kirshenbaum.net/IPA/ascii-ipa.pdf) (PDF). 2001.
+
+3. International Phonetic Association,
+ [The International Phonetic Alphabet and the IPA Chart](https://www.internationalphoneticassociation.org/content/ipa-chart). 2015.
+ Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA).
+
+4. Wikipedia.
+ [International Phonetic Alphabet](https://en.wikipedia.org/wiki/International_Phonetic_Alphabet). 2017.
+ Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA).
+
+5. Wikipedia.
+ [Extensions to the International Phonetic Alphabet](https://en.wikipedia.org/wiki/Extensions_to_the_International_Phonetic_Alphabet). 2017,
+ Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA).