UserGuide: Add some notes about keysym syntax

Fixes: #10745

lib/doc/UserGuide.lyx

@@ -140,11 +140,12 @@ enumitem
 \papercolumns 1
 \papersides 2
 \paperpagestyle default
-\tracking_changes false
+\tracking_changes true
 \output_changes false
 \html_math_output 0
 \html_css_as_file 0
 \html_be_strict true
+\author -712698321 "Jürgen Spitzmüller"
 \end_header
 
 \begin_body
@@ -8336,14 +8337,12 @@ Verbatim
 \end_layout
 
 \begin_layout Verbatim
-
 This is Verbatim.
 \end_layout
 
 \begin_layout Verbatim
 \noindent
 \align block
-
 The following 2 lines are empty:
 \end_layout
 
@@ -8356,7 +8355,6 @@ The following 2 lines are empty:
 \end_layout
 
 \begin_layout Verbatim
-
 Almost everything is allowed in Verbatim:"%&$§#~'`
 \backslash
 }][{|
@@ -8380,7 +8378,6 @@ Verbatim
 \end_layout
 
 \begin_layout Verbatim*
-
 This is Verbatim*.
 \end_layout
 
@@ -45997,7 +45994,7 @@ Key Bindings ! Editing
 \end_layout
 
 \begin_layout Standard
-To add new or modify existing keybindings to your own taste you can use
+To add new or modify existing key bindings to your own taste you can use
  the table in the dialog that lists all \SpecialChar LyX
  functions and the bound shortcuts.
  To find functions easily, they are grouped by categories and the dialog
@@ -46102,6 +46099,62 @@ key combination
 \end_inset
 
 
+\change_inserted -712698321 1503738349
+
+\end_layout
+
+\begin_layout Standard
+
+\change_inserted -712698321 1503740883
+Note, though, that the key combination definition uses a specific syntax.
+ This applies to the designators of specific modifier keys (e.
+\begin_inset space \thinspace{}
+\end_inset
+
+g., 
+\family typewriter
+M
+\family default
+, 
+\family typewriter
+S
+\family default
+, 
+\family typewriter
+C
+\family default
+ for 
+\family sans
+Meta/Alt
+\family default
+, 
+\family sans
+Shift
+\family default
+, 
+\family sans
+Ctrl
+\family default
+, respectively) as well as to the other keys.
+ Note particularly that you cannot use non-alphanumeric characters directly
+ in the definition of the key combination, but must use commands following
+ the Xlib standard instead (please refer to the existing bind files for
+ a model).
+ So if you wanted to bind a command to the key combination 
+\family sans
+Alt+Shift+:
+\family default
+, you needed to specify it as 
+\family typewriter
+M-S-colon
+\family default
+.
+ If you use the dialog to edit key bindings, you don't have to care for
+ these specifics.
+ \SpecialChar LyX
+ transforms your input to the correct syntax.
+\change_unchanged
+
 \end_layout
 
 \begin_layout Subsection

lib/doc/de/UserGuide.lyx

@@ -44807,6 +44807,58 @@ bind „Tastaturkürzel“ „\SpecialChar LyX
 -Funktion“
 \end_layout
 
+\begin_layout Standard
+Beachten Sie hierbei aber, dass die Definition der Tastenkürzel eine spezielle
+ Syntax verlangt.
+ Das betrifft die Symbole für Modifizierungstasten (bspw.
+ 
+\family typewriter
+M
+\family default
+, 
+\family typewriter
+S
+\family default
+, 
+\family typewriter
+C
+\family default
+ für 
+\family sans
+Meta/Alt
+\family default
+, 
+\family sans
+Umschalt
+\family default
+, 
+\family sans
+Strg
+\family default
+) genauso wie die für andere Tasten.
+ Beachten Sie insbesondere, dass Sie keine nicht-alphanumerischen Zeichen
+ in den Definitionen verwenden können.
+ Statt dessen müssen Sie Befehle verwenden, die dem Xlib-Standard folgen
+ (bitte sehen Sie sich die vorhandenen 
+\family typewriter
+*.bind
+\family default
+-Dateien für Beispiele an).
+ Wenn Sie also etwa einen Befehl an die Tastenkombinationen 
+\family sans
+Alt+Umschalt+:
+\family default
+ binden wollten, müssten Sie diese so definieren: 
+\family typewriter
+M-S-colon
+\family default
+.
+ Wenn Sie die Tastenkombinationen im Einstellungs-Dialog bearbeiten, müssen
+ Sie sich um diese Spezifika nicht kümmern.
+ \SpecialChar LyX
+ übersetzt Ihre Tasteneingaben in die korrekte Syntax.
+\end_layout
+
 \begin_layout Subsection
 Tastatur / Maus
 \begin_inset CommandInset label