TRD 05: Data Presentation techniques (Mapping) Quantum GIS ...

6.2 WMS Client
Figure 11: Dialog for adding a WMS server, showing its available layers
Tip 22 WMS LAYER ORDERING
In this version of QGIS, WMS layers rendered by a server are overlaid in the order listed in the Layers section,
from top to bottom of the list. If you want to overlay layers in the opposite order, then you can select Add WMS
layer a second time, choose the same server again, and select the second group of layers that you want to
overlay the first group.
Transparency
In this version of QGIS, the transparency setting is hard-coded to be always on, where available.
Therefore no option for it exists on-screen.
This, in theory, allows you to overlay WMS layers on other layers (raster, vector or WMS) and still see
through to those lower layers.
Tip 23 WMS LAYER TRANSPARENCY
The availability of WMS image transparency depends on the image encoding used: PNG and GIF support
transparency, whilst JPEG leaves it unsupported.
Coordinate Reference System
A Coordinate Reference System is the OGC terminology for a QGIS Projection.
QGIS 0.8 User Guide 45