Labels and annotations
How To: Add a Leader Line to a Text Annotation Feature in an Annotation Feature Class
arcgis desktop - Multiple leader lines on one annotation (non feature-linked) - Geographic Information Systems Stack Exchange
Exercise 3a: Converting labels to annotation—ArcMap
Annotation Scale
arcgis desktop - Labels for Very Small Features Not Displaying - Geographic Information Systems Stack Exchange
Solved: How to not cover marker symbols with leader lines? - Esri Community
arcgis desktop - Preventing symbol rotation of point character symbols combined with line features in ArcMap? - Geographic Information Systems Stack Exchange
GIS Dictionary
Labels and annotations
Creating leader lines for labels in ArcGIS Pro
arcmap - Having different annotations for same feature in ArcGIS Desktop? - Geographic Information Systems Stack Exchange