
The symbol used depends on which Line Reference Numbers system has been adopted in the Drawing Properties: If this style is adopted using the IEC2, IEC4 or IEC-60617 libraries you may feel that the line reference markers are too large, especially when the rung distance is set to lower than 20mm and you’ve used a line reference number system that contains graphics e.g: Some multi-national companies will adopt a drawing standard that is a mixture of International standards with vertical ladders along with line referencing to the US style along with IEC symbols.

The US standard utilises line referencing rather than column/row or column referencing for the purposes of both cross referencing, but also wire numbering and component tagging.
