In the Revit.ini file, the settings in the [Snapping] section enable and disable object snaps and define snap increments.
Corresponds to the list of angular snap increments on the Snaps dialog.
Type = string
Valid values: 0.0001 to 360 degrees, values separated by semicolons
Corresponds to the Angular dimension snap increments option on the Snaps dialog.
Type = integer
Valid values: 0 = Off, 1 = On
Corresponds to the Length dimension snap increments option on the Snaps dialog.
Type = integer
Valid values: 0 = Off, 1 = On
Corresponds to the list of linear snap increments on the Snaps dialog for models that use imperial units.
Type = integer
Valid values: 0 = Off, 1 = On
Corresponds to the list of linear snap increments on the Snaps dialog for models that use metric units.
Type = integer
Valid values: 0 = Off, 1 = On
Corresponds to the Snaps Off option on the Snaps dialog.
Type = integer
Valid values: 0 = Off, 1 = On
Correspond to the Object Snaps settings on the Snaps dialog.
Type = integer
Valid values: 0 = Off, 1 = On
[Snapping] EnableLinearIncrementSnaps=1 ImperialSnapIncrements=4' ; 0' 6" ; 0' 1" ; 0' 0 1/4" ; MetricSnapIncrements=1000 ; 500 ; 100 ; 20 ; 5 ; EnableAngularIncrementSnaps=1 AngleSnapIncrements=90.000° ; 45.000° ; 30.000° ; 15.000° ; 5.000° ; 1.000° ; SnapToEndPoints=1 SnapToMiddle=1 SnapToNearest=1 SnapToWorkPlaneGrid=1 SnapToIntersections=1 SnapToCenters=1 SnapToPerpendicular=1 SnapToTangents=1 SnapToQuadrants=1 SnapToPoints=1 SnapToRemoteObjects=1 SnapToPointClouds=1 SnapsOff=0