Baton sinister

It is a diminutive of the bend sinister and constitutes a narrow strip that runs from the upper right to the lower left of a coat of arms.

Sinister (meaning left in Latin) is merely a directional indicator, and does not carry the negative connotations of the word in modern English.

It is commonly believed to be an indicator of an illegitimate birth in the family line, and is used in this way in literary contexts.

[2][further explanation needed] The baton sinister can be seen in the arms of the Duke of Grafton, descended from an illegitimate son of King Charles II of England.

Today, the College of Arms in England uses a bordure wavy to mark an armiger as illegitimate.