Can any one interpret this sentence?
Rebus principle: When the symbol for one entity is taken over as the symbol for the sounds of the spoken word used to refer to that entity that symbol then comes to be used whenever that sounds occurs in any word.

I know what is 'rebus' but I cannot relate my knowledge to this content . For example the word "for" which is a symbol is replaced with "4" which is another symbol that has similar sound. But the content doesn't refer to another symbol which is "4" so I think the word "four" itself must change to its sound symbol . Can you give me how this development based on this specific content will happen?

Question

Can any one interpret this sentence?
Rebus principle: When the symbol for one entity is taken over as the symbol for the sounds of the spoken word  used to refer to that entity that symbol then comes to be used whenever that sounds occurs in any word.

I know what is 'rebus' but I cannot relate my knowledge to this content . For example the word "for" which is a symbol is replaced with "4" which is another symbol that has similar sound. But the content doesn't refer to another symbol which is "4" so I think the word "four" itself must change to its sound symbol . Can you give me how this development based on this specific content will happen?

Answer

You cannot apply "rebus" to a sentence about rebus, where that sentence is descbinging/explaining "rebus".

Yes you are correct, if the symbol that represents a sound is one symbol /one sound. Then it is the same wherever/whenever it appears. So  the sound/symbol for "for" will always be the same, and the sound/symbol for "four" (a  number) will always be the same.
"for" must retain it's sound/symbol and "four" must retain it's sound symbol.

Rebuses apply only to individual words. The sounds meaning the same or being closely similar are irrelevant. It is their two different symbols that tells us whether it is "for" or "four"

Answer

As much as I wish that I were able to understand it completly threw me off ahhahaa what does it mean? I am using your question is rhetorical