Chapter 2. Default Options
WhiteSpace default options are available under: Utilities> Global Options> Plugin Options> WhiteSpace.

"Spaces" options
Show spaces by default
Space color
Show leading spaces by default
Show inner spaces by default
Show trailing spaces by default

"Tabs" options
Show tabs by default
Tab color
Show leading tabs by default
Show inner tabs by default
Show trailing tabs by default

"Other whitespaces" options
Show other whitespaces by default
Display ISO control chars as whitespaces
Other whitespace color

"Fold guides" options
Show fold guides by default
Show fold tooltips by default
Fold guide color

"Paragraph separators" options
Show paragraph separators by default
Paragraph separators respect indentation
Paragraph separator color

"On save" options
When chosen, these actions are performed when a buffer is saved:
Remove trailing whitespaces
All trailing tabs and spaces are removed, except those preceded by one of the given escape characters. The default escape character is \ (backslash). E.g.
Some Text\   
will be replaced by
Some Text\ 

Tabify/untabify according to soft tabs setting
The soft tabs setting determines whether leading whitespaces should be converted to tabs or spaces.
Tabify leading whitespaces
Leading whitespaces are replaced by a sequence of tabs possibly followed by at most tabSize - 1 spaces. The expanded length of leading whitespaces remains the same.
Untabify leading whitespaces
All tabs are removed from the leading whitespaces and replaced by an equivalent number of spaces. The expanded length of leading whitespaces remains the same.

Chapter 3. Buffer Options
The Buffer options are available from the Plugins> WhiteSpace menu.
The following Buffer options enable you to control the highlighting of spaces, tabs and other whitespaces for a given jEdit buffer. It's also possible to highlight spaces and tabs depending on their position (leading/inner/trailing) in the text.
Show spaces
Show tabs
Show other whitespaces
Show paragraph separators
Show fold guides
Show fold tooltips
Show leading spaces
Show inner spaces
Show trailing spaces
Show leading tabs
Show inner tabs
Show trailing tabs
The following Buffer options control the actions to be taken when a buffer is saved. Note that the last three actions are mutually exclusive.
Remove trailing whitespaces
Tabify/untabify according to soft tabs setting 
Tabify according whitespaces
Untabify leading whitespaces