Hi Rasoul,

The squares mean that some kind of paragraph control (keep together, keep
with next...) has been activated.
If you double-click on the square, the dialog for changing those settings
comes up.
http://word.mvps.org/FAQs/Formatting/NonPrintChars.htm

Regards,
Klaus


"Rasoul Khoshravan Azar" schrieb im Newsbeitrag
...
By applying special format to a paragraph or line a small black squares
appear to the left of the line. What are they and how can I use them?
TIA
Rasoul Khoshravan Azar