Creating resources
Symbol, pattern, or marker from the selection

The right-click menu with the Create resource submenu open: Create symbol, Create pattern, Create marker

The three items

Right-click menu › Create resource, with something selected. What is selected moves into the new resource — "symbol-1", "pattern-1", "marker-1"… — where it was on the canvas, in one step (two, in a document that had no resources yet).

ItemOriginAfterwards
Create symbolthe top-left corner of the bounding boxin place of the selection a use remains that shows the symbol there, selected: the drawing does not change
Create patternthe corner of the bounding box; the tile is as large as the bounding boxthe selection leaves the drawing and you enter the pattern
Create markerthe center of the bounding box: the point that falls on the vertexyou enter the marker; it orients itself along the line