I am working on a schematic/ PCB layout in which +3V3 is from an external source and a second voltage is generated by the output of a switch-mode PSU in the schematic itself (for which I have a net label named +3V3_LEDs).
Despite the current name, the latter will more probably be a different voltage, e.g., +2V2.
The general idea is that I can choose which of the two available voltages are routed to various components such as LEDs via several 3-way solder jumpers.
In that way, I can optimise power consumption by choosing the most appropriate voltage based on Vf of the particular LEDs that are subsequently ordered.
For example, I would pass the lower voltage to the red LEDs and the higher voltage to the green LEDs.
As seen in the graphic, there are symbols of power type (i.e., having their ‘Define as power symbol’ checkbox ticked) such as +Vred and +Vgreen.
Those same symbols are used as drivers for the red/ green dual LED anodes, an example being shown in the following graphic.
I manually annotated all the components on the schematic and was surprised to see the ERC message that some annotations were missing.
I let the system automatically complete the annotation process and observed that annotations were done relating to various net names, which I found surprising.
After completing that automatic annotation, there are no error or warning messages for the schematic ERC.
Moving on to using the PCB Editor, I find that the system appears to have no knowledge about +Vred and +Vgreen 
As seen in the following graphic, there is no ratsnest lines showing between the centres of (in particular JP6 and JP7, which relate to powering for the red and green LEDs).
I have added red and green lines to the graphic to show the ratsnest lines that are missing between the jumpers and the LED anodes.
The system has annotated, for example, the centre of JP7 as ‘Net - (JP7-Pad2)’
I don’t understand why!
In contrast, the +3V3 power symbol has resulted in expected behaviour (that name showing in the jumper pads and there being associated ratsnest lines).
I tried adding ‘+Vred’ as a net label (i.e., in addition to the power symbol of that same name); although that results in the name showing in the jumper middle pad, there is no ratsnest line resulting.
Presumably, I could add the same ‘+Vred’ as a net label to the LED connection to achieve a result, i.e., a connection between the jumper and red LED anode.
However, the question arises as to why the power symbols +Vred and +Vgreen seem to be getting disregarded?!
There is no complaint from the rules checker in relation to these power symbols.
I should imagine that it would complain that there is no power input to such as +Vgreen, which are simply the middle of 3-way solder jumpers.
I was expecting to have to add power flags - since there was no complaint from the system, I didn’t add power flags.
In contrast, for +3V3, the system realised that it was a power flag with no on-schematic source so I had to add a power flag for it to get rid of the error message, as was expected.
