Minima on US plates. Confused.
 

Just struggling looking at the minima on these US plates. Can some one plz tell me what units they are in etc. For instance, 276/18 200 (200-1/2).

And what does all this mean including the bracketed numbers.

Thanks in advance.

Presuming it's US Gov't charts (NACO) that you are using.
276/18 is your Decision Height in feet (QNH/MSL).
276/18 is visibility, RVR in hundreds of feet.
200 is height above touchdown zone in feet(QFE).
(200-1/2) is for military pilots.
For more info, try the following links:
http://www.faa.gov/library/manuals/a...ying_handbook/
(Specifically Ch8, pp8-23 through 8-25)
http://www.faa.gov/library/manuals/a...ures_handbook/
Hope this helps.

1/2 mile is also used if RVR is not available.

samusi and misd are both right; RVR in US are predicated in feet, eg; 6 means 600ft, 24 means 2400ft etc. 1/2 means 1/2 statute miles; as opposed to ICAO RVRs in meters and visibility in meters and kilometers.