Field numbering
Field-based numbering is the simplest and most robust. Pages, Captions and Footnotes are examples of numbering done with fields.
A field in a Word document is simply a placeholder that contains "the instructions for working out what should go here," rather than the text itself. In this case, it contains the instructions for displaying and incrementing a set of numbers. A field is simply a small section of computer code embedded in a special container that tells Word to interpret the contents as computer instruction code instead of text.
Word automatically inserts and maintains the fields for some forms of field-based numbering. The most commonly used numbering fields are pages, number of pages (page X of Y) and footnotes.
Captions
Captions are a special case: if you use Word's Insert>Caption command, it inserts the fields for you, but the field itself is a good old-fashioned SEQ(uence) field, and some people prefer to insert them manually so they have complete control over the formatting and incrementing.
A SEQ field can belong to only one sequence and it can produce only one level of numbering. You can can number your headings using SEQ fields: if you do, you have to define a named sequence for each level of numbering. You also need to handle your own re-setting of each level when a higher level occurs.
Field-based numbering is very stable and rugged, but a little fiddly and
complex to use or maintain. Many professional writers such as technical writers
use field-based numbering exclusively, because of its stability and ruggedness.
They can export or import documents containing field-based numbering to any of
the Word file formats. They can convert the text backwards and forwards from
Word 6, 95, 97, 98 and 2000 as many times as they like, and the field-based
numbering will always be correct.
Clause numbering
Legal clause numbering requires that a single paragraph contains more than one number. Word 97 introduced a new field called the LISTNUM field, designed especially for this. Regrettably, it will not down-convert to versions below Word 97, unless you unlink all the fields (by pressing Ctrl+A followed by Ctrl+Shift+F9) prior to saving in Word 6/95 (or earlier) format.
For clause numbering, you should stick to the AUTONUM field unless you are sure the documents will never needed to be edited in an earlier version of Word than Word 97 .
Page X of Y
Word can automatically produce "page X of Y" page numbering. Word performs this numbering with a pair of automatically inserted fields. Unfortunately, one of the fields has had a notorious bug in it since Word 6: you can end up with a sequence such as "page 1 of 1, page 2 of 2, page 3 of 3 ..." where the second part of the page X of Y does not update correctly. The bug is actually in Word's pagination algorithm. Word makes up the print image of the page before it has finished paginating the document, so it really doesn't yet know how many pages there are ... Service Release 1 for Word 2000 finally fixed the bug. See separate article Page X of Y displays or prints as Page 1 of 1, Page 2 of 2 etc. for some workarounds for earlier versions.
Technical writers rarely use "page X of Y", and where they do, they work-around the bug by constructing page X of Y manually using a bookmark on the last page of the document and a cross-reference to its page number.
