Generalise configuration-setting substitution across the guides

unix-installation-and-configuration-guide/docs/configuration-parameters/configuration-files.md

@@ -40,14 +40,6 @@ If the same name is defined multiple times within a configuration file then the
 
 An array can be used to define file paths, for example, `WSPATH: ["/dir1", "/dir2"]`. The only parameters which can be defined as arrays are **WSPATH**, **WSEXT** and **CFEXT**.
 
-## References to other Configuration Parameters
-
-Configuration parameters that are string values can include references to other configuration parameters (irrespective of where they are defined) using square bracket delimiters. For example, `MySetting: "[DYALOG]/MyFile"` will replace `[DYALOG]` with the value of the **DYALOG** configuration parameter.
-
-If the referenced configuration parameter is not defined then no substitution will take place; the reference, including the square bracket delimiters, will remain in place.
-
-To include literal square brackets in a string, prefix them with a `\` character.
-
 ## Nested Structures
 
 Configuration files support nested parameter structures by defining an object that corresponds to the structure. For example:

unix-installation-and-configuration-guide/docs/configuration-parameters/configuration-parameters.md

@@ -11,3 +11,11 @@ Dyalog can be customised using configuration parameters. These can be set in var
 This provides a great deal of flexibility, enabling a user to override one setting with another. For example, a "usual" workspace size (**MAXWS**) can be defined in the user configuration file, but be temporarily superseded by entering a different value when starting a Dyalog Session from the command line.
 
 For more information on configuration files, see [Configuration Files](configuration-files.md). For more information on environment variables, see [Environment Variables](environment-variables.md).
+
+## References to Other Configuration Parameters
+
+Configuration parameters can include references to other configuration parameters using square bracket delimiters. For example, `MySetting: "[DYALOG]/MyFile"` will replace `[DYALOG]` with the value of the **DYALOG** configuration parameter.
+
+If the referenced configuration parameter is not defined then no substitution will take place; the reference, including the square bracket delimiters, will remain in place.
+
+To include literal square brackets in a string, prefix them with a `\` character.

windows-installation-and-configuration-guide/docs/configuration-files.md

@@ -111,26 +111,14 @@ WSPATH: ["/dir1", "/dir2"]
 
 The only parameters which may be defined as arrays are **WSPATH**, **WSEXT** and **CFEXT**.
 
-#### References to other Configuration Parameters
+## References Relative to the Configuration File
 
-Configuration parameters which are string values may include references to other configuration parameters (regardless of where they are defined) using square bracket delimiters. For example:
-```apl
-MySetting: "[DYALOG]/MyFile"
-```
-
-will replace `[DYALOG`] with the value of the **DYALOG** configuration value.
-
-If the string inside the `[]` delimiters is "`.`", the "`.`" is replaced is replaced with the path of the directory containing the configuration file itself. Therefore,
+Within a configuration file, a [reference to another configuration parameter](configuration-parameters/configuration-parameters.md#references-to-other-configuration-parameters) can also refer to the location of the file itself. If the string inside the `[]` delimiters is "`.`", the "`.`" is replaced with the path of the directory containing the configuration file. For example:
 ```apl
 FILENAME: "[.]/x.txt"
 ```
 
-will set the parameter **FILENAME** to a value which is a reference to a file called `x.txt` in the same directory as the configuration file defining it.
-
-Note that:
-
-- If the referenced configuration parameter is not defined then no substitution will take place; the reference, including square bracket delimiters, will remain in place.
-- To include square brackets in a string, prefix the '[' with a '\' character.
+will set the parameter **FILENAME** to a value that is a reference to a file called `x.txt` in the same directory as the configuration file defining it.
 
 #### Nested Structures
 

windows-installation-and-configuration-guide/docs/configuration-parameters/configuration-parameters.md

@@ -39,3 +39,19 @@ You can change parameters in the Registry in one of two ways:
 
 - Using the Configuration dialog box that is obtained by selecting *Configure* from the *Options* menu on the Dyalog APL/W session. See ["The Configuration Dialog Box"](../configuring-the-ide/configuration-dialog/configuration-dialog-general-tab.md) for details.
 - By directly editing the Windows Registry using `REGEDIT.EXE` or `REGEDIT32.EXE`. This is necessary for parameters that are not editable via the Configuration dialog box.
+
+## References to Other Configuration Parameters
+
+Configuration parameters can include references to other configuration parameters using square bracket delimiters. For example:
+```apl
+MySetting: "[DYALOG]/MyFile"
+```
+
+will replace `[DYALOG]` with the value of the **DYALOG** configuration parameter.
+
+Note that:
+
+- If the referenced configuration parameter is not defined then no substitution will take place; the reference, including square bracket delimiters, will remain in place.
+- To include square brackets in a string, prefix the `[` with a `\` character.
+
+`[=DOCUMENTS]` is a pre-defined substitution parameter that is replaced with the location of the user's Documents folder (for example, `C:\Users\Bob\Documents`).