Found in the Select Menu (Edit Menu > Select), Add to Palette adds the present selection to the Selections Palette. Refer to the Selections Palette article to learn more.

How to add a selection to the Selections Palette

1. Go to Window Menu > Selections Palette or use the shortcut command shift A. The Selections Palette will open.
2. Use the selection tools to create your selection.
3. Save the selection to the Selections Palette by going to the Edit Menu > Select > Add to Palette, or simply use the keyboard shortcut ⌘7. The selection will appear in the palette with the default name “Selection” followed by a number i.e. Selection 1, Selection 2 and so on.
4. Double click on the word Selection and enter a more relevant name for the selection.
5. Press the None button in the Selections Palette or use the keyboard shortcut ⌘D to remove that selection from your file.
6. Repeat steps 2 to 5 for other selections and save the design. The selections will be saved with the design if you save as .ava4 format.