What Does "By ATC" Mean for an SID Route? I can understand that altitudes may be "by ATC", but why can a route also be marked with "by ATC"? All SID routes need prior clearance by ATC, right?

For example, in SID RWY 16 for ZGSZ/SZX, MEPOG-7X and LKC-7X are "by ATC", while others are not. I know that LKC-7X is not a regular route flown, but still: what does "by ATC" mean here?


(Source: ZGSZ AD 2.24-7F, AIP China)
It means, don't file that transition yourself.  ATC may assign it, but it's their option to assign it or leave you on what you filed.