The New England Historical and Genealogical Register report format is perhaps a familiar example. The ODT uses a depth-first presentation order. Take the left-most of the unexplored branches, again proceeding downward along the extreme left edge of that subtree. Repeat from step 2 until the apex is again reached by backtracking along the right-most branch. This procedure is guaranteed to visit each node in a tree at least once.
Simple adjustments accommodate multiple marriages.
The end result looks like an outline, hence the name. The example to the right shows how this works for a limited number of generations, and no spouses shown. Indention Successive generations are indented by the width of one character. This, together with the generation numbering, is usually sufficient to allow visual groupings. In order to facilitate printing of the ODT, long lines are presented in pieces so that no data escapes beyond the print margins.