I was inspecting a PCB with a magnifying glass and noticed some of the light brown ceramic smd capacitors have 3 digit markings on them. Is there a "standard" of what these markings stand for? The first digit looks like a K with a line above it (K̄), and the other two digits are always a letter followed by a number. Example: K J4K̄J4 or K A5K̄A5