An "L" (as in L401) stands for a coil, choke, or an inductor. These are usually measured in miliHenrys (mH). I'm not for sure what LL00026 could mean.
A "C" (as in C423) is for capacitor. The "474" is it's value....470000 picofarads (pf)......or more commonly known .47 microfarads (µf). The CS400 might be it's voltage rating....400 volts. There's also several different kinds of capacitors (mylar, ceramic, electrolytic, polypropylene, polyester, etc.). Without a picture, it's impossible to say what you have.....but at (possibly) a 400 volt rating....I'd guess polyester or polypropylene.
Edward