R1C5 can only be <6>

R3C3 can only be <5>

R5C5 can only be <8>

R6C4 can only be <2>

R8C4 can only be <5>

R8C6 can only be <4>

R9C5 can only be <9>

R2C6 can only be <7>

R2C4 can only be <1>

R4C6 can only be <3>

R6C6 can only be <6>

R6C2 can only be <3>

R6C8 can only be <8>

R4C4 can only be <7>

R1C7 is the only square in row 1 that can be <5>

R9C2 is the only square in row 9 that can be <5>

Intersection of column 2 with block 1. The value <4> only appears in one or more of squares R1C2, R2C2 and R3C2 of column 2. These squares are the ones that intersect with block 1. Thus, the other (non-intersecting) squares of block 1 cannot contain this value.

R1C3 - removing <4> from <347> leaving <37>

Intersection of column 7 with block 9. The value <4> only appears in one or more of squares R7C7, R8C7 and R9C7 of column 7. These squares are the ones that intersect with block 9. Thus, the other (non-intersecting) squares of block 9 cannot contain this value.

R7C9 - removing <4> from <1467> leaving <167>

R9C9 - removing <4> from <23478> leaving <2378>

Squares R1C2<14>, R2C2<46> and R3C1<16> in block 1 form a comprehensive locked triplet. These 3 squares can only contain the 3 possibilities <146>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the block.

R1C1 - removing <1> from <1379> leaving <379>

R2C1 - removing <6> from <369> leaving <39>

Squares R1C2 and R4C2 in column 2 and R1C8 and R4C8 in column 8 form a Simple X-Wing pattern on possibility <1>. All other instances of this possibility in rows 1 and 4 can be removed.

R1C9 - removing <1> from <134> leaving <34>

Squares R3C1 and R3C9 in row 3 and R7C1 and R7C9 in row 7 form a Simple X-Wing pattern on possibility <6>. All other instances of this possibility in columns 1 and 9 can be removed.

R2C9 - removing <6> from <346> leaving <34>

R8C1 - removing <6> from <2368> leaving <238>

R8C9 - removing <6> from <2368> leaving <238>

Squares R1C9 and R2C9 in column 9 form a simple locked pair. These 2 squares both contain the 2 possibilities <34>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.

R8C9 - removing <3> from <238> leaving <28>

R9C9 - removing <3> from <2378> leaving <278>

Squares R1C9 and R2C9 in block 3 form a simple locked pair. These 2 squares both contain the 2 possibilities <34>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the block.

R1C8 - removing <3> from <139> leaving <19>

R2C8 - removing <3> from <369> leaving <69>

Squares R8C8 (XYZ), R8C2 (XZ) and R9C8 (YZ) form an XYZ-Wing pattern on <2>. All squares that are buddies of all three squares cannot be <2>.

R8C9 - removing <2> from <28> leaving <8>

R9C1 is the only square in row 9 that can be <8>

Intersection of row 9 with block 9. The value <2> only appears in one or more of squares R9C7, R9C8 and R9C9 of row 9. These squares are the ones that intersect with block 9. Thus, the other (non-intersecting) squares of block 9 cannot contain this value.

R8C8 - removing <2> from <236> leaving <36>

Squares R2C8 (XY), R8C8 (XZ) and R2C1 (YZ) form an XY-Wing pattern on <3>. All squares that are buddies of both the XZ and YZ squares cannot be <3>.

R8C1 - removing <3> from <23> leaving <2>

R8C2 can only be <6>

R5C1 can only be <1>

R8C8 can only be <3>

R2C2 can only be <4>

R7C1 can only be <7>

R9C8 can only be <2>

R9C7 can only be <4>

R9C9 can only be <7>

R4C8 can only be <1>

R2C9 can only be <3>

R1C2 can only be <1>

R2C1 can only be <9>

R1C9 can only be <4>

R4C2 can only be <2>

R1C8 can only be <9>

R5C9 can only be <2>

R3C1 can only be <6>

R7C3 can only be <4>

R7C7 can only be <1>

R9C3 can only be <3>

R7C9 can only be <6>

R3C7 can only be <2>

R3C9 can only be <1>

R1C3 can only be <7>

R1C1 can only be <3>

R2C8 can only be <6>