ONELAB-syntax-for-Gmsh-and-GetDP.md

@@ -169,9 +169,18 @@ Here's the list of attributes available for all ONELAB parameters:
 
 * `AutoCheck 0|1`: Allows to disable automatic "check" (rebuild of the interface) when the value is changed.
 
-* `GmshOption "string"`: Treats the parameter as the name of a Gmsh option (e.g. `Mesh.Algorithm`). Can also be used to force a database reset (with `ResetDatabase`), or a full model reset (with `Reset`). 
+* `GmshOption "string"`: Treats the parameter as the name of a Gmsh option (e.g. `Mesh.Algorithm`).
 
-* `ServerAction "string"`: Performs the ONELAB server action `string` when the parameter is changed. Currently supported actions are `Reset` (to force a full model reset), `ResetDatabase` (to force a full database reset) and `Reset var1 var2 ...` (to force a reset of the listed variables). 
+* `ServerAction "string"`: Performs the ONELAB server action `string` when the parameter is changed. Currently supported actions are `Reset` (to force a full model reset), `ResetDatabase` (to force a full database reset) and `Reset name1 name2 ...` (to force a reset of the listed variables). The `Reset name1 name2 ...` form allows to create master/slave variables where the slave variables can still be edited server-side, contrary to `ReadOnly` variables. For example:
+
+```
+DefineConstant[
+  a = {1, Name "var1", Label "Master variable", ServerAction "Reset var3"}
+  b = {a*2, Name "var2", Label "Slave (x 2) variable", ReadOnly 1}
+  c = {a*2, Name "var3", Label "Editable slave (x 2) variable"}
+  d = {a*2, Name "var4", Label "Standard (x 2) variable"}
+];
+```
 
 * `Label "string"`: Alternative label used in the graphical user interface, replacing the part of `Name` located after the last `/`.