Label:Format::Units:Description.
~ (tilda) is a line-break marker in DESCRIPTION.
The colon is a field marker. Do not use a colon in Description (or any field...).

Event ID field.
Seq_Num:ASCII_Integer::none:A unique sequence number for the occultation. This sequence number is used to identify the occultation in the Asteroids or Planets list.

Observer field.
Obs_Num:ASCII_Integer::none:A numeric identifier of each observer within an occultation event.
Obs_Name1:UTF8_String::none:Name of the principal observer. Many early records do not include a first name or initials. If the name is PREDICTION, the entry relates to a point on a predicted occultation path.
Obs_Name2:UTF8_String::none:Name of a second observer. Many early records do not include a first name or initials.  Not set for PREDICTION.
Obs_Name_etal:ASCII_Integer::none:0 = false, 1 = true. More than 2 observers were involved, with their names not included.  Not set for PREDICTION.
Obs_Nearby:UTF8_String::none:Indicates the name of a nearby location. This field is only used for checking site coordinates (if needed).  Not set for PREDICTION.
Obs_Country:UTF8_String::none:Indicates the Country, or for the USA, Canada and Australia the state within that country. The codes used are 'ISO ALPHA-2' and 'ISO ALPHA-3'.  Not set for PREDICTION.
Obs_Longitude_EW:UTF8_String::none:Value = E or W - for the hemisphere (East or West) of the site longitude.
Obs_Longitude_DEG:ASCII_Integer::deg:Degree component of the site longitude.
Obs_Longitude_Min:ASCII_Integer::arcmin:ArcMinute component of the site longitude.
Obs_Longitude_Sec:UTF8_String::arcsec:ArcSecond component of the site longitude.
Obs_Latitude_NS:UTF8_String::none:N or S - for the hemisphere (North or South) of the site latitude.
Obs_Latitude_DEG:ASCII_Integer::deg:Degree component of the site latitude.
Obs_Latitude_Min:ASCII_Integer::arcmin:ArcMinute component of the site latitude.
Obs_Latitude_Sec:UTF8_String::arcsec:ArcSecond component of the site latitude.
Obs_Altitude:ASCII_Integer::m:Altitude of the site above Mean Sea Level.  For PREDICTION, always set to 0.
Obs_Datum:UTF8_String::none:Code for the geodetic datum used for the site coordinates~' ' = WGS84~N = NAD1927~E = ED1950~T = Tokyo~G = GB1936~* = unspecified , or other datum. For PREDICTION, always set to WGS84.
Obs_Aperture:ASCII_Integer::cm:Aperture of the telescope (or optical system) used to make the observation. Not set for PREDICTION.
Obs_Telescope:UTF8_String::none:Code for the type of telescope (or optical system) used to make the observation. Not set for PREDICTION~' ' = unstated~1 = Refractor~2 = Newtonian~3 = Compound optical systems (such as Schmidt-Cassegrain)~4 = Dobsonian~5 = Binoculars~6 = other~7 = None~8 = Electronic (small-aperture self-aligning telescope with an electronic detector).
Obs_Method:UTF8_String::none:Code for the method of recording or observing the occultation. Not set for PREDICTION~' ' = unspecified (for events before 2000, most likely visual)~a = Analogue or digital video~b = Digital SLR-camera video~c = photometer~d = sequential images (e.g. a series of images with a CCD camera)~e = Drift scan (the star field drifts across a single exposure of a stationary camera)~f = Visual~g = Other.
Obs_TimeSource:UTF8_String::none:Code for the time source used to measure the event times. Not set for PREDICTION ~' ' = unspecified~a = GPS (Global Positioning System, 1-pps signal)~b = NTP (Network Time Protocol)~c = Mobile or other phone~d = Radio time signal~e = internal clock of the recorder. Typically used with multi-station deployments, with calibration occurring some time before and after the event~f = Stopwatch. Typically the stop watch is calibrated against another time source, in particular a Radio time signal~g = Other.

Conditions field.
Stability:UTF8_String::none:Code for the atmospheric stability of the image. Not set for PREDICTION~' ' = unstated~1 = Steady~2 = Slight flickering~3 = Strong flickering.
Transparency:UTF8_String::none:Code for atmospheric transparency. Not set for PREDICTION~' ' = unstated~1 = Clear~2 = Fog~3 = Thin cloud (Magnitude loss less than 2 mags)~4 = Thick cloud (magnitude loss greater than 2 mags)~5 = Broken opaque cloud (that is, observed through gaps between clouds)~6 = star faint~7 = by averted vision.
SN:ASCII_Real:%4.1f:none:Signal-to-noise ratio in a recorded light curve. Not regularly provided. Not set for PREDICTION.
TimeAdjustment:ASCII_Real:%7.2f:s:An adjustment to the time base of the observer. This is rarely used. It is only used when the chord location for an observer is clearly displaced from the chords of other observers - indicating a problem with the time base of the observer. Usually the weight accorded to the observation is reduced, often to a zero-weight. Not set for PREDICTION.
Free_Text:UTF8_String::none:A free-text field for comments from the observer. The length of the field is unlimited. Most fields contain useful information. The text in the field is not 'managed'; as a result there may be spelling errors, and comments that have little meaning to anyone not involved in the event analysis. Comments from the person collating the observations may be preceeded by 'Ed.' (but not always). Events that have been observed from the Kuiper Airborne Observatory (KAO), SOFIA, and an F18 airplane are noted in this field.

D fields.
D_Hr:ASCII_Integer::hr:Hour component of the Disappearance event. The hour is always +ve, and can be greater than 24 when observations extend from one day to the next.
D_Min:ASCII_Integer::min:Minute component of the Disappearance event.
D_Sec:UTF8_String::s:Second component of the Disappearance event.
D_EventCode:UTF8_String::none:Code for the event type~D = occultation of the main star~d = occultation by a companion star~G = occultation of the main star by a satellite~g = occultation of a companion star by a satellite~M = Miss~m = Miss with 2nd star. Used only when observer has an event with the main star, and a positive exclusion of an event involving the 2nd star~N = occultation by a ring. The D and R times are for opposite arms of a ring. Where there is a D+R for an arm of a ring, the mid-time is specified, with the duration being given in Free_Text~n - for asteroids (or planets) known to have one or more rings, and an occultation by that ring(s) could not be reliably detected. Most commonly this relates to the star not crossing the orbit of any ring, or the absence of material in the portion of a ring crossed by the star. However there may be other explanations for the non-detection.~C = Not seen - e.g. because of cloud (such events are generally not included)~e = artificial D time of the primary body of an asteroid with satellites - for use when an occultation by the primary was not observed. The site location (Obs_LONGITUDE and Obs_LATITUDE) and event time are set on the basis of a prediction.
D_Uncertainty:UTF8_String::s:Reported uncertainty in the time of the event. Empty = no uncertainty reported; default uncertainties are 0.5 secs (Obs_Method = a, b or c and Obs_TimeSource=a, d or f), 1.5 secs (Obs_Method = a, b or c and Obs_TimeSource=b, c, e or g), and 1.0 secs for all other Obs_Method values.
D_PE:UTF8_String::s:Personal Equation that has been applied to the time made by a visual observation. When Empty, no PE has been supplied, and the event time is assumed to have been corrected for PE.
D_Weight:ASCII_Integer::none:Weight allocated to the event when the default weight is over-ridden. Set to 0 to exclude the event from analysis. The default weights are~5 for Obs_Method = a~4 for Obs_Method = b or c~3 for Obs_Method = d or e~1 for Obs_Method = f.
D_PlotCode:UTF8_String::none:Code for controlling whether the event should be plotted in a reduction analysis~x = plot neither the Disappearance or Reappearance events~y = plot only the Disappearance event~z = plot only the Reappearance event.

R fields.
R_Hr:ASCII_Integer::hr:Hour component of the Reappearance event. The hour is always +ve, and can be greater than 24 when observations extend from one day to the next.
R_Min:ASCII_Integer::min:Minute component of the Reappearance event.
R_Sec:UTF8_String::s:Second component of the Reappearance event.
R_EventCode:UTF8_String::none:Code for the event type~R = occultation of the main star~r = occultation by a companion star~B = occultation of the main star by a satellite~b = occultation of a companion star by a satellite~M = Miss~m = Miss with 2nd star. Used only when observer has an event with the main star, and a positive exclusion of an event involving the 2nd star~N = occultation by a ring. The D and R times are for opposite arms of a ring. Where there is a D+R for an arm of a ring, the mid-time is specified, with the duration being given in Free_Text~n - for asteroids (or planets) known to have one or more rings, and an occultation by that ring(s) could not be reliably detected. Most commonly this relates to the star not crossing the orbit of any ring, or the absence of material in the portion of a ring crossed by the star. However there may be other explanations for the non-detection.~C = Not seen - e.g. because of cloud (such events are generally not included)~f = artificial R time of the primary body of an asteroid with satellites - for use when an occultation by the primary was not observed. The site location (Obs_LONGITUDE and Obs_LATITUDE) and event time are set on the basis of a prediction.
R_Uncertainty:UTF8_String::s:Reported uncertainty in the time of the event. Empty = no uncertainty reported; default uncertainties are 0.5 secs (Obs_Method = a, b or c and Obs_TimeSource=a, d or f), 1.5 secs (Obs_Method = a, b or c and Obs_TimeSource=b, c, e or g), and 1.0 secs for all other Obs_Method values.
R_PE:UTF8_String::s:Personal Equation that has been applied to the time made by a visual observation. When Empty, no PE has been supplied, and the event time is assumed to have been corrected for PE.
R_Weight:ASCII_Integer::none:Weight allocated to the event when the default weight is over-ridden. Set to 0 to exclude the event from analysis. The default weights are~5 for Obs_Method = a~4 for Obs_Method = b or c~3 for Obs_Method = d or e~1 for Obs_Method = f.
R_PlotCode:UTF8_String::none:Code for controlling whether the event should be plotted in a reduction analysis~x = plot neither the Disappearance or Reappearance events~y = plot only the Disappearance event~z = plot only the Reappearance event.
