RTF Syntax

Help RTF statements are presented to the Microsoft Help compiler in topic files, which are specified in the [FILES] section of a Help project file. To the Help compiler a topic file consists of RTF statements, control symbols, groups, and unformatted text. Each RTF statement consists of a backslash (\) followed by an RTF statement name and delimiter:

\statement-name<delimiter>

RTF statements must be separated from subsequent text or statement parameters by a delimiter. A delimiter can be one of the following:

nA space.

In this case, the space is considered part of the statement.

nA digit or minus sign (-), which indicates that a numeric parameter follows.

The subsequent digit sequence is then delimited by a space or any character other than a letter or digit. In other words, the parameter can be a positive or negative number. If a numeric parameter immediately follows the statement name, this parameter becomes part of the statement. The statement is then delimited by a space or a non-alphabetic or non-numeric character in the standard manner.

nAny character other than a letter or digit.

In this case, the delimiting character terminates the statement but is not considered part of the statement. A “letter” is an upper- or lowercase ASCII letter.

For example, the following line demonstrates usage of the \tab statement and a space delimiter:

left column\tab right column

When a space is used as a delimiter, the Help compiler discards it. If any other character is used, the compiler processes it as text or the start of another RTF statement. For example, if a backslash is used as a delimiter, the compiler interprets it as the beginning of the next RTF statement.

Certain statements control properties (such as bold and italic) that have only two states. When the RTF statement has no parameter or has a non-zero parameter, the statement is used to turn the property on. When the RTF statement has a 0 (zero) parameter, the statement is used to turn the property off. For example, \b turns on bold, whereas \b0 turns off bold.

Some statements, referred to as destinations, mark the beginning of a collection of related text. An example of a desination is the \footnote group, where the Help-specific text follows the statement. Destination statements and their following text must be enclosed in braces, as in this example:

{\footnote main_contents}

A control symbol consists of a backslash (\) followed by a single non-letter. They require no further delimiting.

Note:

Although control symbols are compact, there aren’t too many of them. But the number of possible statements is not limited. The parameter is partially incorporated in control symbols, so that if an application does not understand a control symbol, it can ignore the corresponding parameter as well.

A group consists of Help RTF statements and text enclosed in braces ({ }). The opening brace { indicates the start of the group, and the closing brace } indicates the end of the group, as shown in this example:

{       group start, and
}       group end.

Formatting specified within a group affects only the text within that group. Text within a group inherits any formatting of the text preceding the group.

Unformatted text consists of any combination of 7-bit ASCII characters. Although characters whose values are greater than 127 are not permitted in topic files, the \’ statement can be used to insert them in the final Help file. The Help compiler treats spaces as part of the text, but it discards carriage return and linefeed characters.

RTF statements, control symbols, and braces constitute control information. Text grouping is used to define the format and placement of text and graphics in the Help file. All other characters in RTF text constitute plain text.

Because the backslash character (\) and braces ({ }) have specific meanings in RTF, they must be preceded with a backslash if you want to use them as plain text, as shown by the control symbols \\, \{, and \}.