Positioning accuracy of Here 3 / Here 3+


I would like to calculate confidence intervals and I have some doubts.
Could somebody give me a description what the positioning accuracy exactly means in case of Here 3 / Here 3+?
From the manual: 3D FIX: 2.5 m / RTK: 0.025 m
However, the precision is not given, it could refer to the 50% of the data or 96%.
Also the direction is not specified neither.

Many thanks,