diff --git a/README.md b/README.md
index 2a07352..e3bfa5a 100644
--- a/README.md
+++ b/README.md
@@ -48,10 +48,15 @@ The font must be installed at `/usr/local/share/fonts/г/ГОСТ_тип_А.ttf`
 |---|---|
 | Unit | Symbol shown in the left panel (e.g. `U`, `mA`, `%`) |
 | Range label | Text inside the coloured bar on the right (e.g. `5mA`) |
+| Mapping | **Linear** or **Log**. Log spaces values geometrically (major ticks evenly spaced, minor ticks crowding toward the high end) and requires Min and Max greater than 0 |
 | Min / Max | Numeric range of the scale |
 | Major intervals | Number of major tick intervals |
 | Minor per interval | Minor ticks between each pair of major ticks |
 | Labels | Number of numeric labels; Labels − 1 should divide evenly into Major intervals |
+| Custom labels | Optional comma-separated labels that override the calculated numbers; their count sets the number of labels. Leave blank to auto-calculate |
+| Label size (mm) | Font size of the numeric labels, in millimetres (default `9`) |
+
+Calculated numbers are rendered in fixed-point notation at 4 significant figures — never scientific (e.g. `10000`, not `1e+04`).
 
 ## Container