Locked Candidates
Points.
Locked Candidates is a single digit method where all
candidates in one line/box are located in a threecell intersection with
another box/line. Digits outside the intersection can be removed from the
second set, the covering set. Locked candidates are pointing if the
first set is a box, or claiming if not
Locked Candidates, Claiming, Rows. The three candidates in row 5 make a truth that is covered by box 5, thus the red candidate can be removed. The row containing the truth is shaded gray
and the box is shaded yellow.


Locked Candidates, Claiming, Cols. The two candidates in column 6 make a truth that is covered by box 2, thus the 5 red candidates can be removed from the box.


Locked Candidates, Pointing, Row. The two digit 1 candidates in box 5 form a truth that is covered
by row 5, thus the 2 red candidates in row 5 can be removed.


Locked Candidates, Pointing, Cols. A pair of digit 7 candidates in box 5 form a truth that is covered by column 5, thus the 2 red candidates in column 5 can be
removed.


