four zeppelin symbols

ive done countless research over these symbols as i am a zeppelin extremist but on fact eludes me. What does the fifth symbol mean? the symbol i refer to is the one with the three triangles. the triangle is from sandy denny who did guest vocals on the battle of evermore. does anyone know its meaning?

Led Zep’s fourth album Led Zeppelin IV only has four symbols in its name.

It sounds like you’re referring to something that’s probably no longer visible to anyone that has the CD, rather than the LP:

Forgot to add the article you’re most likely referring to…
What do the four symbols on Led Zeppelin’s 4th album mean?

That’s a hell of a thing. Another thing lost (almost) as the music industry drives a technology change that’s an improvement, but cuts corners by omitting internal material.