
70 Chapter Four Web Browsing by Example
from the document top. For example, the
nth parameters of the tag pattern
in Figure 4.2(b) indicate a region from the second H3 to the third H3 em-
bodied in the second cell (the second TD in the first TR) of the second
TABLE.
To identify the starting position of the user-specified portion, the tag
pattern contains all HTML elements that mark up the starting position.
Only layout elements that affect the page layout, such as TABLE, TR, TD,
UL,
LI, H1-H6, P, and HR, are included in the pattern, while font style ele-
ments, such as FONT and B, are not considered. ...