In each documentation page you have a search field in top left corner.
If you search seq[T] in system module, you get a list:
search results
system : GC_ref[T](x: seq[T])
system : GC_unref[T](x: seq[T])
system : items[T](a: seq[T]): T
system : len[T](x: seq[T]): int
system : xlen[T](x: seq[T]): int
system : pop[T](s: var seq[T]): T
system : `$`[T](x: seq[T]): string
system : isNil[T](x: seq[T]): bool
system : shallow[T](s: var seq[T])
random : shuffle[T](x: var seq[T])
system : `==`[T](x, y: seq[T]): bool
system : add[T](x: var seq[T]; y: T)
system : `&`[T](x, y: seq[T]): seq[T]
system : getRefcount[T](x: seq[T]): int
system : `&`[T](x: seq[T]; y: T): seq[T]
system : `&`[T](x: T; y: seq[T]): seq[T]
system : `@`[T](a: openArray[T]): seq[T]
system : mitems[T](a: var seq[T]): var T
system : safeAdd[T](x: var seq[T]; y: T)
system : del[T](x: var seq[T]; i: Natural)
Hey, I didn't know that trick. Very useful.
Thanks.