6.4 Columns
6.4.1 SGML
Normally, use a <bkdv3 type="col" n=""> ... </bkdv3> tag. Columns are bibliographical structural units within pages and encompassing lines. Pages that have both uncolumned and columned text may be tagged n="0" for the uncolumned lines, and n="1" and n="2" for the columned sections. TEI P3 (pp. 889-90, 906) gives two options: an unstructured <cb> tag, and <col> to use when recording the way a standard edition divides the text. Again, it is worth making clear that columns are determined by the printer, not the author.
<bkdv3 type="col" n="1">
<ttdv2 type="alpha"> <heading>A</heading>
<ttdv3 type="entry">
<p> <ttdv4 type="lemma" lemma="A"
n=1>A</ttdv4> <explan>The first letter of all Alpha{\-}
bets, is (as it is a letter) a
Substantiue:</explan> whence;
...
</bkdv3>
<bkdv3 type="col" n="2">
...
6.4.2 COCOA
Columns may be a feature of bibliographical structure, that is, a division nested between the page and the line, even if other forme-work on the page, such as the header or running-title, pagination, signature, etc., is not also in columnal form but occupies the width of the entire page. <bkdiv1> would then be the gathering, <bkdv2> the forme page, <bkdv3> the page line, <bkdv4> the column, and <bkdv5> the column line. Note that this structure nests the columns under the first line of the page, normally the running-title and page number, but below just a border. Here is an example from Cotgrave's French-English dictionary (1611).
<bkdv2 sigB1v>
<bkdv3 line1>
<bkdv4 col1>
<bkdv5 line1><ttdv2 alpha> <tt heading>A B B
<tt entry><lemma abandonnement>
<bkdv5 line2><p><form 1>Abandonnement: <gen>m. <tgt> an abandonning, quitting, for\-
....
<bkdv4 col2>
Normally, however, use only the non-structural <col 1> ... <col 2> ... tags.