| "self" | "descendant" | "child" | "descendant-or-self"
| "attribute" | "following-sibling" | "preceding-sibling"
| "parent" | "ancestor" | "ancestor-or-self" | "preceding" | "following"
| "self" | "descendant" | "child" | "descendant-or-self"
| "attribute" | "following-sibling" | "preceding-sibling"
| "parent" | "ancestor" | "ancestor-or-self" | "preceding" | "following"