Maybe a mistake of Ch.4 A brief Explanation of Linking

[jnchen]

i think it should be PT_DYNAMIC

[nermalcat69]

hey @jnchen, its not a mistake 😄 ,
The PT_INTERP is a program header entry in an ELF file that specifies the path to the dynamic linking runtime aka interpreter.

PT_INTERP is correct because it is the standard way to specify the path to the dynamic linking runtime in an ELF file. This(PT_INTERP, interpreter which is responsible for loading and resolving libraries at runtime ) allows ELF executables to be smaller and faster to load at runtime.

also read this too