This is the most logical option. Tabs to add an indentation level, the width of that is unimportant and can be configured by each user. Spaces to align, since t

This is the most logical option. Tabs to add an indentation level, the width of that is unimportant and can be configured by each user. Spaces to align, since they're like any other character in a mono spaced font thereby perfectly matching the line above.