Articulation placement follows stem direction (opposite the stem side)

A staccato dot, accent, tenuto line, or marcato roof sits on the side of the notehead away from the stem — above the notehead when the stem points down, below when the stem points up (so the mark never collides with the stem or beam).

A rendered accent glyph appears on the SAME side as the stem (e.g. below a stem-up note, colliding visually with the stem), which is purely a renderer placement failure since Gradus's data model carries no author-controllable side field.

Gould, Behind Bars, ch. Articulation, gives this as the standard placement rule; Ross, The Art of Music Engraving, agrees and further notes marks under a beam group are placed consistently on one side for the whole group.

This rule is about where marks land on the page, so it can only be judged after engraving. Collision and spacing faults live here.