This blog shows the shortcuts (i.e. abbreviations) for the most common XPath axes (plural of axis):
[table id=2 /]

Reference: https://our.umbraco.com/documentation/reference/templating/macros/xslt/xpath-axes-and-their-shortcuts

Also see example on the sites below:
https://www.way2tutorial.com/xml/xpath-axes.php
https://www.w3schools.com/xml/xpath_axes.asp