You are correct...it is the fixed distance marker that is the focus of this question. This marker is a visual aid that is useful for any aircraft. For the 767-300, the previous post shows why many do not "plan" a touchdown prior to this point. Specifically:
1. Boeing does not recommend a TD prior ("Special attention must be given to establishing a final approach that assures safe threshold clearance and gear touchdown at least 1,000 feet down the runway.")
2. Main Gear height above the ground at the threshhold is minimal.
The full touchdown zone is an acceptable position to TD in most cases. For runways in the US (9,000 feet or longer), and for the 767-300, that represents the zone between the 1,000 foot markers and the final TDZ stripes that are located at 3,000 feet down the runway.
If flying a SE Cessna, the 1,000 ft markers are still a meaningful visual aid, be it on a runway with a length of 4,000 ft or 10,000 ft .
>The markings are coded to define the distance from the threshold and are often used as ‘an acceptable landing area’, but this is aircraft dependant and is rarely mandated except in theory for Cat 2/3 operations.