Help me with text emphasis

[Peggy Thompson <Peggy_Thompson -at- CCMAIL -dot- OSTI -dot- GOV>]

 The following paragraph is typical of what I work (struggle)
 with--it contains any number of search terms, user input, and
 directives that require special emphasis in the text (these are
 bookended by asterisks in the example below). Kindly give me
 your suggestions for uses of italic, bold, bold italic, or even
 a different font for these various kinds of emphasis. (We strive
 for clarity and, dare I say it, elegant simplicity.)

     "For example, to search the Words in Text field for either
     the term *oil* or the term *petroleum*, enter *oil,
     petroleum*. The resulting set will contain records having
     either the term *oil* or the term *petroleum*. The operator
     OR searches for records that meet *any* of the search
     criteria.

     "If you wish to OR *between* fields, you must use the Guided
     Search."

 Another question: when we use italics and bolding, we want to
 use a font for each that is a bit different from the text font
 (otherwise, we find our bolding and italic getting lost). I say
 that if we do that, ALL instances of italic and bold must adhere
 to that same font--that is, if you bold a word such as
 *petroleum* above and you bold chapter references, both must be
 in the same font. (Some here have argued that *petroleum* should
 be in a different bold font for special emphasis, while a bolded
 chapter reference should simply be the regular text font
 bolded.)

 And one MORE question: how do you handle internal references to
 chapters and subheadings? Do you put chapter heads in italic,
 heading in bold, or some such? Or would you use the same
 emphasis technique for both the chapter titles and the
 subheadings?

 Sorry for these amateurish questions--we are updating our style
 sheets which clearly are out of step with the modern world. ;)
 (And no, we are not trying to change for change's sake!)

 You may reply directly to me. Many, many thanks.