> a few screwups where a line or two in a 4-spaced file actually contains 3 spaces. Why this happens... is beyond me In my experience it's usually from copy-pa

> a few screwups where a line or two in a 4-spaced file actually contains 3 spaces. Why this happens... is beyond me In my experience it's usually from copy-paste, usually because the cursor wasn't at the right position when pasting. The cursor not being at the right position because you deleted some spaces to reduce the level of indentation before pasting, but didn't do the right number. While tab inserts the right number of spaces, delete still deletes spaces. Also occasionally due to a find-replace that accidentally included a leading space, which can be hard to see when the find/replace boxes are in a proportional font.