allout-chart-subtree is a compiled Lisp function in `allout.el'.

(allout-chart-subtree &optional LEVELS VISIBLE ORIG-DEPTH PREV-DEPTH)

Produce a location "chart" of subtopics of the containing topic.

Optional argument LEVELS specifies a depth limit (relative to start
depth) for the chart. Null LEVELS means no limit.

When optional argument VISIBLE is non-nil, the chart includes
only the visible subelements of the charted subjects.

The remaining optional args are for internal use by the function.

Point is left at the end of the subtree.

Charts are used to capture outline structure, so that outline-altering
routines need to assess the structure only once, and then use the chart
for their elaborate manipulations.

The chart entries for the topics are in reverse order, so the
last topic is listed first. The entry for each topic consists of
an integer indicating the point at the beginning of the topic
prefix. Charts for offspring consist of a list containing,
recursively, the charts for the respective subtopics. The chart
for a topics' offspring precedes the entry for the topic itself.

The other function parameters are for internal recursion, and should
not be specified by external callers. ORIG-DEPTH is depth of topic at
starting point, and PREV-DEPTH is depth of prior topic.