For loop type
taxonomy_term, here are the query parameters and fields.
children- Set true to include only child terms
exclude- Exclude terms by ID(s) or slug(s)
hide_empty- Hide terms not assigned to any post - true or false (default)
id- Get terms by ID(s)
include- Include terms by ID(s) or slug(s)
name- Get terms by name/slug(s)
order- Order: asc (ascending) or desc (descending)
orderby- Order by one of: name, title (default), term_id, menu_order, count
orderby_field- Order by custom field
orderby_field_number- Order by custom field whose value is a number
parent- Get terms by its parent term's ID or slug
parents- Set true to include only top-level parent terms
post- Corresponding post ID(s) for term retrieval or "current" for current post
taxonomy- Get terms by taxonomy
terms- Alias for "include"
ancestors- Ancestor term IDs (or loop instance) from lowest to highest level; Set reverse=true to go from top-level down
children- Children term IDs (or loop instance)
count- Post count
id- Term ID
name- Term name
parent- Parent term ID (or loop instance)
posts- Loop instance of posts that belong to current term
taxonomy- Taxonomy name (or loop instance)
title- Term title
url- URL to term archive page
taxonomy attribute as a shortcut.
<Loop taxonomy=category> <Field title /> </Loop>
The above is the same as:
<Loop type=taxonomy_term taxonomy=category> <Field title /> </Loop>
Taxonomy tag provides another way to express it.
<Taxonomy category> <Term title /> </Taxonomy>