The following AQL documentation page: Advanced searching: AQL - Assets Query Language has some AQL queries in it.

It will benefit users if we can add a short explanation of the syntax used in complex queries, for example:

object HAVING inboundReferences(Label IN (${Portfolios.label${0}}))

• Label is a function to represent the object's text attribute, set as its Label, regardless of the Attribute's name (by default it is Name, but it may be customized!)
• ${Portfolios.label${0}} - is a placeholder to represent the value in the Portfolio customfield.
• The ".label" refers to the text string seen on this customfield in the issue view (while ".id" will refer to the value's ID).
• The ${0} indicates the Portfolio field may carry multiple values, and this"index 0" indicates to refer to the values as an array of values, and not a single string (...${2} will refer to the 2nd value in the array).
• Since we use the ALL index (${0}) we cannot use the '=' operator, hence we must use IN (<value1,value2,....>)

Adding explanation to syntax will help users in understanding and compiling their complex AQLs