Closure produces interesting results when displaying numbers (sums from "below") on tables of accounts and journals, etc. The idea is that all numbers displayed in a column should add up. With closure on (i.e. a closure index selected), the numbers for intermediary branches must display empty. Otherwise columns would appear to add up incorrectly. Technically, the numbers are all correct but it looks funny and prompts a lot of confusion.
Shown below is another example, all journals in the database, sorted by name closure and displaying proof numbers (for the "leaves" only, and not the "branches", except the grand totals of the "root" branch).
