By default, the AllowFormatInvalidOnTyping property is True, which indicates that the current line is highlighted as soon as the user types. The AllowFormatInvalidOnTyping property specifies whether the FormatInvalid property is applied on the current line, while typing into the control. By default, the FormatInvalid property is "<fgcolor=FF0000><s> </s></fgcolor>", which indicates that invalid lines are shown in red as showing in the following screen shot. If the FormatInvalid property is "", the control does not highlight the invalid lines.

An invalid line is not evaluated, and so no result is being shown. The FormatResult property specifies the HTML format of the result. The FormatTotalResult / FormatSubTotalResult  property formats the Total / Sub-Total lines. The FormatCountResult / FormatSubCountResult property specifies the HTML format of lines that contains Count or SubCount aggregate function.

The list of supported built-in HTML tags is:

• <b>bold</b>
• <i>italic</i>
• <s>strikeout</s>
• <u>underline</u>
• <fgcolor=RRGGBB>fgcolor</fgcolor>
• <bgcolor=RRGGBB>bgcolor</bgcolor>
• <font face;size>text </font> displays portions of text with a different font and/or different size. For instance, the <font Tahoma;12>bit</font> draws the bit text using the Tahoma font, on size 12 pt. If the name of the font is missing, and instead size is present, the current font is used with a different size. For instance, <font ;12>bit</font> displays the bit text using the current font, but with a different size.