Magento 2 – Passing argument from backoffice in Category Layout Update XML field to frontend module or phtml

In Magento 1 I sometimes used this way to pass an argument to a category, directly from the back office

Category > Custom Design tab > XML Design Update

<reference name="product_list">     <action method="setData"><key>giftCardId</key><value>955</value></action> </reference> 

Could you tell me what will be the equivalent syntax in Magento 2, Using the same way:

Category > Design > Layout Update XML

The main idea is to pass a value for a specific category, that could be retrieved in a custom module in frontend.

Edit: I know that I can add a custom category attribute to do that too, but the point is really, does an equivalent syntax exists.