Beam adjustment screw :)

[Riko_imp]

I haven't done it, but I assume the vertical adjustment is done by the headlight case side mounting bolts/screws.

you mean the bolts at the 'ears'
as you might know and see they make the light go up or down = horizontal

Just in cas, you never know.v
Horizontal
[url=https://picoolio.net/image/IdZd]

Vertical
[url=https://picoolio.net/image/IdZq]

Hmm I was looking at the hand and camera reflection and that white line, and they all looked the same. Didn't notice the rim pivoting horizontally, although I clearly see that now. However, I also don't understand how the horizontal adj has anything to do with the vertical adjustment.

it has nothing to do with it I was just mentioning that there are 2 adjustment options for the direction of the headlights.
Adjust up and down at the 'ears' its horizontal

Left to right adjustment is vertical....

On a bike where the headlight turns with the bars, I was at first baffled as to why Honda thought this adjustment was necessary. But the more I thought about it, I guess it makes good sense. Even if they attempted to make them perfectly straight from the factory, could there be a margin of error? This allows each bike to be adjusted to a suitable or desired precision.

Though I hate to admit it, I found this adjuster screw by accident. When I first went to disassemble the lamp to install the LED, I started here first.
After turning and turning and turning for what I found to be much too long of a time, there it was.....my headlamp was awkwardly turned hard to the left.
Definitely one of those "ah ha" moments.

indeed, i thought it was funny when i discovered that tweak option

I accidentally discovered it too when removing the headlight assembly

it has nothing to do with it I was just mentioning that there are 2 adjustment options for the direction of the headlights.
Adjust up and down at the 'ears' its horizontal

Left to right adjustment is vertical....
Man, I really misread this thread. When you said

"So it allows a vertical adjustment rather than the known horizontal adjustment."

I thought you were talking about that screw allowing a vertical adjustment.

my bad

English, tough language

it has nothing to do with it I was just mentioning that there are 2 adjustment options for the direction of the headlights.
Adjust up and down at the 'ears' its horizontal

Left to right adjustment is vertical.... my bad

English, tough language
nah, don't bother, I do it all the time in Dutch too

[PowerDubs_imp]

All this time and nobody corrected the error?

Vertical is UP & DOWN- Horizontal is LEFT & RIGHT- like the horizon...

[Riko_imp]

whatever, point was, the screw adjusts the left/right sideway direction of the headlight

[White Dog_imp]

ver·ti·cal
ˈvərdək(ə)l/Submit
adjective
1.
at right angles to a horizontal plane; in a direction, or having an alignment, such that the top is directly above the bottom.
"the vertical axis"
synonyms: upright, erect, perpendicular, plumb, straight up and down, on end, standing, upstanding, bolt upright
"workers enter through a vertical shaft"
2.
archaic
denoting a point at the zenith or the highest point of something.
noun
1.
a vertical line or plane.
"the columns incline several degrees away from the vertical"
2.
an upright structure.
"we remodeled the opening with a simple lintel and unadorned verticals"

hor·i·zon·tal
ˌhôrəˈzän(t)l/Submit
adjective
1.
parallel to the plane of the horizon; at right angles to the vertical.
"a horizontal line"
synonyms: level, flat, plane, smooth, even; More
2.
merging companies that are engaged in the same stage or type of production.
"a horizontal merger"
noun
1.
a horizontal line, plane, etc.