The first step is to figure out the desired look for the list, then the spacing that will be needed between the numbers and the text. For this example, I decided on larger, bolder numbers using a serif font. I created one line of text with the numbers "00." keyed in manually and styled. Zeros are used because they are almost always the widest numerals. Two zeros were used because the items in the list are more than nine, so they will span to double digits. From the rulers, the approximate spacing can now be determined. This line of text will be deleted once the Paragraph Style has been created.
A quick way to create a bulleted or numbered list is to type the list, select it, and then click the Bulleted List or Numbered List button in the Control panel. These buttons let you turn the list on or off and switch between bullets and numbers. You can also make bullets and numbering part of a paragraph style and construct lists by assigning styles to paragraphs.
Currently the barcodes on a book's back cover (or inside a mass-market paperback book's front cover) are EAN-13; they may have a separate barcode encoding five digits called an EAN-5 for the currency and the recommended retail price.[47] For 10-digit ISBNs, the number "978", the Bookland "country code", is prefixed to the ISBN in the barcode data, and the check digit is recalculated according to the EAN13 formula (modulo 10, 1x and 3x weighting on alternating digits).
After struggling with multi-level lists I finally figured out one of the major problems. If you are struggling but you haven't already read other tutorials, you definitely should, but this tip will be useful no matter what. Before setting or re-setting the list for a given heading, select "None". Then go back and select the list you want. For some reason if you try to switch directly from one list to another it does horrid things that I do not understand. Hope that helps.

In a legal document, it's rare for every paragraph in the document to be numbered. Usually, you change between numbered paragraphs and non-numbered (plain) paragraphs of text. When Word sees you switching between these types of formats, it usually tries to help by restarting your numbered list back at "1" (or the first value of your list, such as "A"). There are a few different ways to make the number follow the last number of your paragraphs. In Word, this is called Continue from Previous List.
Thanks very much for your prompt reply, which reassured me that I was on the right path. From having read various Help topics, I suspected that I'd have to use an Excel data source for the numbers. Fortunately, my knowledge of Excel was good enough to know about the drag and drop facility to create automatic sequential numbering, so the data source creation was easy. In the end, it was the mail merge (no surprises?) which proved a tad tricky, but I got there in the end. I've used MM many times and quite happily in Word documents, but for Publisher label format, it was of course a bit different. The important bit that I had to discover for myself was the significance of, after getting to the Print stage, going into Print options, to Publication & Paper Settings, and selecting Multiple Pages per Sheet (& in my case, also "Single-sided" cos my default of duplex printing had come up). But TA-DA!  All is fine now. Thanks very much again.
This feature is easiest to use when you combine it with Word's built-in heading styles. However, you can map a custom heading style to the multilevel numbering feature—it just takes more work. Word handles nine levels, but any document with more than four levels should receive a serious developmental edit. More than four becomes confusing and perhaps worse, unreadable.
A multi-level list is a list that describes hierarchical relationships between the list paragraphs. These lists are also called outline lists because they resemble outlines. The list’s numbering scheme (as well as indentations) show rank as well as how items are subordinate to one another. You can tell where each paragraph fits in the list with respect to the paragraphs before and after it. You can include up to nine levels in a multi-level list.
In the Bullet or Number Position section, set the Alignment to Right. The Left Indent is where the text will start. The First Line Indent is the amount of space that should be subtracted from the left indent to determine where the period after the number will be positioned. This was determined in the first step with the spacing placeholder text. Leave Tab Position blank and check Preview to see the options take effect in the highlighted text. Make any needed adjustments to the positions, and when you are satisfied, click OK.
1. digit, figure. 2. Number, sum both imply the total of two or more units. Number applies to the result of a count or estimate in which the units are considered as individuals; it is used of groups of persons or things: to have a number of items on the agenda. Sum applies to the result of addition, in which only the total is considered: a large sum of money. 20. copy, edition.