Merge branch '93-predefined-string-section' into 'master'

Resolve "Predefined string section"

Closes #93

See merge request OPAL/documentation/manual!192

format.asciidoc

@@ -218,6 +218,23 @@ STRING L2=LEP&STRING(X+1);
 The second example converts the value of the expression `X+1` to a
 string and appends it to `LEP`, giving the string `LEP2`.
 
+[[sec.format.predefined-strings]]
+==== Predefined String Attributes
+
+_OPAL_ recognizes some specific string names using a list of predefined strings.
+Consequentially, attributes of type `PredefinedString` should only accept
+strings that are contained in a predefined set of strings according to their
+internal description. If the provided string is not contained in the predefined
+set, an exception is thrown, since this string is marked as a protected keyword
+and cannot be used to name an object. Most of the string attributes in _OPAL_
+have been defined based on `PredefinedString` to prevent the user from entering
+variable names that are used internally for another functionality. All these
+predefined string attributes do not have to be enclosed in quotes,
+unlike regular strings. The list of accepted strings as well as the default
+value, if any, are added to the `--help-command` message
+(see <<tab_CommandLineArg>>).
+
+
 [[sec.format.alogical]]
 === Logical Expressions
 

tutorial.asciidoc

@@ -56,8 +56,10 @@ OPAL > Finished reading startup file.
 One can exit from this session with the command
 `link:control#sec.control.stop[QUIT;]` (including the semicolon).
 
-For batch runs _OPAL_ accepts the following command line arguments: +
+For batch runs _OPAL_ accepts the command line arguments shown in <<tab_CommandLineArg>>:
 
+.Command line arguments
+[[tab_CommandLineArg,Table {counter:tab-cnt}]]
 [cols="<1,<1,<4",options="header",]
 |=======================================================================
 |Argument |Values |Function