Horizontal Rules (HRs) are content separators. The Dotted Rule is used to separate 'like' content, while the Solid Rules separate sections of 'different' types of content. The 'Light' solid rule can be used in cases where content is grouped within the same section.
Horizontal-Rules
Usage: Separates content within and outside of containers
Vertical Rules

Vertical-Rules

Usage: Follow same as above – use to designer's discretion
Download: HRs PSD, VRs PSD