# What does this "Not Installed" symbol mean on the data sheet?

I am designing a circuit that uses the TI TPS561201 buck converter. Reading the data sheet, I am slightly confused with the notation of "Not Installed" next to some of the components.

### Questions:

• What is the purpose of including an uninstalled component?
• In what scenario would I include the capacitors in my circuit?

With capacitor C4, for example, why would the component be drawn in the schematic but then labeled "Not Installed"? I have attached the schematic with the symbols highlighted.

• C4 may have caused instability at certain gain/voltage settings. This was most likely found during final testing and flagged RED.
– user105652
Jun 6 '18 at 4:06
• In general, "not installed" components are options that generate different versions of the board and/or were detected as problematic during debug and integration and eliminated. In the first case, they will appear installed in some variants of the board, and uninstalled in others. In the latter case, if the component produced a problem, it will be removed or corrected in a later layout of the board. Jun 6 '18 at 4:12