Honeywell Performance Series User Manual page 7

The TVU Lab symbol.
This symbol indicates that the product has been safety tested by
the TUV Lab.
The Direct Current symbol.
This Direct Current symbol indicates that the product operates
direct current.
This symbol indicates that the product is to be used indoors.
The CE Compliance logo.
This logo indicates that the product conforms to the relevant
guidelines/standards for the European Union harmonization
legislation.
The Protective Earth symbol.
This symbol indicates that the marked terminal is intended for
connection to the protective earth/grounding conductor.
This symbol is used to direct attention to important information.
This symbol warns that the corresponding action could result in an
electric shock.
This symbol indicates On/Standby functionality of the
corresponding control/button/switch.
v