diff --git a/__notations__.txt b/__notations__.txt
new file mode 100644
index 0000000000000000000000000000000000000000..040f77271c75f3031406f29a63ec410e08e13bca
--- /dev/null
+++ b/__notations__.txt
@@ -0,0 +1,13 @@
+som=soma
+ext=extension
+
+map=binary, int8 or uint8 array (/!\ python keyword; map_ used instead)
+bmp=boolean map
+lmp=labeled map (intXX or uintXX array)
+
+ep=extension end point, or extremity (e.g. ep_bmp)
+
+n=number of (e.g. n_somas)
+nfo=info (e.g. som_nfo)
+
+tintegers=tuple of integers
diff --git a/extension.py b/extension.py
index 66db159d454364dfc89bc56ab55dd176859e8153..7f0eb85fbd5575480a307e59239f5aa27a309445 100644
--- a/extension.py
+++ b/extension.py
@@ -19,12 +19,7 @@ min_area_c = 100
 
 class extension_t(glial_cmp_t):
     #
-    # bmp=boolean map
-    # lmp=labeled map (intXX or uintXX array)
-    # map=extension map (map=binary, int8 or uint8 array))
-    # ep_=end point
-    # soma_uid: connected to a soma somewhere upstream (as opposed to downstream extensions)
-    # extensions: downstream (as opposed to being upstreamed connected)
+    # soma_uid: connected to a soma somewhere upstream
     #
     __slots__ = ("scales", "end_points", "soma_uid", "__cache__")
 
diff --git a/glial_cmp.py b/glial_cmp.py
index 740f5d07b36235660b837360f64d53b7e0c368ea..ab971eb828073cb99dfbcc774e30c6ba35f7c183 100644
--- a/glial_cmp.py
+++ b/glial_cmp.py
@@ -8,6 +8,8 @@ import numpy as np_
 
 
 class glial_cmp_t:
+    #
+    # extensions: connected downstream (i.e. going away from the soma)
     #
     __slots__ = ("uid", "sites", "connection_path", "extensions", "img_shape")
 
diff --git a/main.py b/main.py
index 50a2b3179bf1dc451f1cd9a32069929cec82389e..798b991fd753aafee3e4f3fff58cf272ee6c408d 100644
--- a/main.py
+++ b/main.py
@@ -32,8 +32,8 @@ costs = 1.0 / (image + 1.0)
 
 
 # --- Initialization
-som_nfo = {}  # som=soma, nfo=info
-ext_nfo = {}  # ext=extension, nfo=info
+som_nfo = {}
+ext_nfo = {}
 axes = {}
 
 # n_somas = 0
diff --git a/soma.py b/soma.py
index 39459bedca907a0bb421e6c6e5fa32966c78135a..d37492d3be2a3eb3fc8fe9320cd9ec00e3ec8aaa 100644
--- a/soma.py
+++ b/soma.py
@@ -19,10 +19,6 @@ som_ext_path_t = namedtuple_t("som_ext_path_t", "extension length path idx")
 
 
 class soma_t(glial_cmp_t):
-    #
-    # bmp=boolean map
-    # lmp=labeled map (intXX or uintXX array)
-    # map=extension map (map=binary, int8 or uint8 array))
     #
     __slots__ = ("contour_points",)
 
diff --git a/type.py b/type.py
index 7bad96613bed7fd3d5aaac4ba975a6ed274099e9..52e9d842d30e31d1b04ca1d6dacf2c009441cd71 100644
--- a/type.py
+++ b/type.py
@@ -5,7 +5,7 @@ import numpy as np_
 
 array_t = np_.ndarray
 
-tintegers_h = Tuple[int, ...] # tintegers=tuple of integers
+tintegers_h = Tuple[int, ...]
 
 number_h = Union[int, float]