(++) or (+-) orientation

These refer to the orientation of local regions of sequence similarity between two sequences.

• (++) orientation means that the regions of sequence similarity are in the same orientation (e.g. 5' end of the matching sequence is to the right)
• (+-) orientation means that the regions of sequence similarity are in opposite orientations (e.g. 5' end of one matching sequence is to the right, while the 5' end of the other matching sequence is to the left)