You can search through any one note or through notes in all categories. You can also define a replacement string to use for replacement.
The check boxes are:
1. Ignore case:
Checked, the search will not be case sensitive
2. Wrap around:
Checked, the search will continue at the beginning of the note if a match is not found after reaching the end... (if the Search All check box is checked, the search will wrap to the first scrap item upon not finding a match in the last note of the last category.
3. Search all:
Checked, the search will check all notes in all categories.
NOTE: You can cancel a search by holding down the Command key and hitting the '.' key.