The selection mask toolbar can be used to control what entity types can be selected in the graphics area. When you enable selection mode, you can click an icon to disable the ability to select that entity type.
Point Selection Mask - controls the ability to select point geometry.
Line Selection Mask - controls the ability to select line geometry.
Arc/Circle Selection Mask - controls the ability to select arc geometry.
Spline Selection Mask - controls the ability to select spline geometry.
Contour Selection Mask - controls the ability to select contour entities.
Surface Selection Mask - controls the ability to select surface geometry.
Point Pattern Mask - controls the ability to select point pattern geometry.
Text Selection Mask - controls the ability to select text geometry.
Linear Dimension Mask - controls the ability to select linear dimensions.
Radial Dimension Mask - controls the ability to select radial dimensions.
Angular Dimension Mask - controls the ability to select angular dimensions.
Point Dimension Mask - controls the ability to select point dimensions.
Select All Masks - selects all selection masks so that all entity or dimension types can be selected.
Clear Masks - clears the selection of all selection masks so that no entity or dimension types can be selected. This makes it easier when you only want to turn on a small number of selection masks.
TIP: When you perform a feature or a function that automatically enables selection mode, if any of the selection-mask icons are unavailable, then you cannot select that entity type for the feature or function. In this case, the software automatically sets the Selection Masks to allow proper selection for the function.