Lock icon next to attribute of class

[bezkintos]

Hi,

Please explain me if you know why is there a lock icon next to every attribute of every class I create in my UML class diagrams. It is the same as in this picture http://www.sparxsystems.com/enterprise_architect_user_guide/projects_and_teams/locked_element_indicators.html. On this page it is explained the meaning of red and blue exclamation mark, but nothing is said about lock icon next to attributes.
Also, I found and downloaded from Internet several UML diagrams (*.eap) and when I open them in Enterprise Architect there is no lock icon next to the attributes in all classes, but when I add an attribute in some existing class (or make a new class and add atribute) than that attribute has lock icon... Why? What does that mean? It seems I have no restrictions on the use of such class with "locked" attributes...

[qwerty]

Indicates if the scope is private.

q.

[bezkintos]

Hi qwerty,

Thank you very much. This was my first time in Enterprise Architect and I would expecting "-", "+", "#" for scope. When I saw the "lock" I thought it has something to do with project security and lost half a day in that direction (mainly going crazy during that time ...) and it hasn't occur to me to try something else because I was convinced it has something to do with project security (although that didn't have any sense to me).
Anyway, thanks again!