--- a/sd-card.rst	Sat Feb 17 19:24:27 2024 +0200
+++ b/sd-card.rst	Sat Feb 17 23:00:15 2024 +0200
@@ -27,7 +27,7 @@
 Speed
 =====
 
-SD Speed Class:
+SD Speed Class (a number inside "C" symbol) write speed:
 
 ====== =========
 Class  Min Speed
@@ -39,7 +39,7 @@
 10     10MB/s
 ====== =========
 
-UHS Speed Class:
+UHS Speed Class (a number inside "U" symbol) write speed:
 
 ====== =========
 Class  Min Speed
@@ -48,6 +48,44 @@
 3      30MB/s
 ====== =========
 
+Video Speed Class (a number after "V" symbol) write speed:
+
+====== =========
+Class  Min Speed
+====== =========
+6      6MB/s
+10     10MB/s
+30     30MB/s
+60     60MB/s
+90     90MB/s
+====== =========
+
+.. note:: UHS-I bus interface can only support V6 to V30 speed class memory cards. UHS-II is
+          required for V60, V90.
+
+Express Speed Class (a number after "E" symbol) write speed:
+
+====== =========
+Class  Min Speed
+====== =========
+150    150MB/s
+300    300MB/s
+450    450MB/s
+600    600MB/s
+====== =========
+
+Video resolution minimum requirements:
+
+================== ==============
+Video resolution   Speed class
+================== ==============
+640x480   (SD)     C2, C4, U1, V6
+1920x1080 (FullHD) C6, U1, V6
+4k                 C10, U1, V10
+8k                 V60
+================== ==============
+
 https://support-in.wd.com/app/answers/detailweb/a_id/36273/~/specifications-and-compatibility-for-sd%2Fsdhc%2Fsdxc-memory-cards
   Specifications and Compatibility for SD/SDHC/SDXC Memory Cards.
-
+https://www.kingston.com/en/blog/personal-storage/memory-card-speed-classes
+  A guide to speed classes for SD and microSD Cards.