[2.0.76] Why can't some Entities be used as Signals in the Circuit Network?

[L3000]

Today, i wanted to add a map tag to my Yumako Farm, so i wanted to use the icon of a yumako tree for it. But that icon cannot be selected in the GUI. Since this GUI is the "Select a signal" GUI, it also cannot be used as a signal in the circuit network.
When comparing the "Environment" categories of this GUI and the Factoriopedia, i noticed several differences. The following Factoriopedia entries about entities do not have a signal counterpart:

• The "Fish" entity
• The "Tree" that is generated on nauvis
• The "Tree" that is planted using "Tree seed"
• "Dead tree - desert"
• "Ashland tree"
• "Flaming ashland tree"
• "Yumako tree"
• "Jellystem"
• "Lickmaw"
• "Sunnycomb"
• "Water cane"
• "Big rock"
• The "Space platform hub" in the "Space" category

Now i am wondering why this is the case, because all other entities do have signals, for example "Slipstack", "Boompuff", "Big sand rock" and "Huge rock".

I expected that all of the entities listed in Factoriopedia would have a signal counterpart.

Here is a comparison of the "Environment" categories of the "Select a signal" GUI and Factoriopedia:

05-09-2026, 11-00-03.png (822.87 KiB) Viewed 91 times

[Rseding91]

Entities aren't included if their icon is identical to the item counterpart. Additionally entities aren't included if they're marked as hidden (the hub), additionally entities aren't included if they're merged into other entities (most trees are merged into one entry).