This is not the only page in the VMS with kind of "index". I think a prospective way of looking at it might be trying to bring forward a reasonable use case that would require introducing some kind of index, to begin with. Then think over the patterns observed in the index, this could narrow the scope.
In this case it is evidently not as simple as plain enumeration/ordered list. Perhaps some type of table content. The number of items is fifteen. What is fifteen? Some characters in the middle column are very rare - why would that be? Next, all are single, bar air. Does that mean that air is to be treated as a sigle glyph elsewhere? And so on...
(To make it clear, I have no ready idea to propose).
In this case it is evidently not as simple as plain enumeration/ordered list. Perhaps some type of table content. The number of items is fifteen. What is fifteen? Some characters in the middle column are very rare - why would that be? Next, all are single, bar air. Does that mean that air is to be treated as a sigle glyph elsewhere? And so on...
(To make it clear, I have no ready idea to propose).