I want to set a projection to selected lines in a database, but it applies the projection to all lines

Symptom/Problem:
Unable to set a projection specifically to selected lines in a database, it is being applied to all lines.

Environment:
This resolution applies to all versions of all Geosoft products.

Resolution:
If the user wishes to apply a projection to selected data, use the Line selection tool to select those lines to be projected separately, then create a subset database (Database Tools > Window data > Subset database). This new database will contain only the selected lines, and you can apply your projection to this new database.

Root Cause:
Projects are always applied to a entire database, regardless of which lines are selected. It is not expected that the user would keep different data with more than one projection in a single database.