4 LofC Signals distinguishes it from, for example, 2 Line of Communication Signals. There were a number of different LofC Signals regiments, each with a different number.
Within 4 LofC, as with other regiments, there were a number of companies and alongside these a number of sections as you can see from the sheet you posted. The extract shows only No 1 Company deploying initially with the sections listed. We only see him in 4 Company in 1940. 2 Construction Section (my error earlier calling it Communications section) is on the sheet so he is on the page you posted!
MaxD