The settings in the Style tab control styling of HTML text.
Bold. The before and after fields hold the opening and closing tags for bold text and default to <b> and </b>. Stored in $HTMLBoldStart and $HTMLBoldEnd.
Italic. The before and after fields hold the opening and closing tags for italic text and default to <i> and </i>. Stored in $HTMLItalicStart and $HTMLItalicEnd.
Underline. The before and after fields hold the opening and closing tags for underlined text and default to <u> and </u>. Stored in $HTMLUnderlineStart and $HTMLUnderlineEnd.
Strike through. The before and after fields hold the opening and closing tags for struck-through text and default to <strike> and </strike>. (Equivalent to setting the $HTMLStrikeStart and $HTMLStrikeEnd).