# ACF - Reference Types

Reference types help easily build cross-reference between Shopify objects by allowing users to select one or multiple handles based on type of reference field.

There are 6 reference types in ACF. All value produced by ACF is either in string (non-repeatable field) or JSON string (repeatable field).

• When attribute “Allow selection of multiple values” is checked, each value will be separated by |, for example: hello|world|2020, book|shoes|pen|eraser.
• Product, Collection fields can be edited in Editor tab via Shopify resource picker.

• Page, Blog, Article, Linklist fields can be edited in Editor tab via selection field editor.

• In case you don’t see item you want to select, press “load more…” button.