What is Takanoha in Japanese Katana terminology?

The term "Takanoha" (鷹ノ羽, たかのは) refers to a specific pattern of file marks (Yasurime, やすりめ) on a Japanese sword. In this pattern, the file marks are angled upwards from the edge (Ha) and the spine (Mune) towards the center of the blade. This pattern is named "Takanoha" because it resembles the feathers of a hawk (Taka in Japanese). Additionally, because it also resembles the fronds of ferns such as bracken and ostrich ferns, which belong to the fern family (Shida in Japanese), it is also referred to as "Shidayasuri" (羊歯鑢, しだやすり). This pattern is often seen in the works of swordsmiths from the Yamato tradition and the Seki tradition.