metadataFileFormat: 'metadata.txt' file format definition
In dgpreatoni/cameratraps: Camera Trap Data Management and Analysis

List of valid key:value pairs that can be found in a cameratraps metadata.txt file.

Inside any camera trap directory, and optionally inside a site directory, a "metadata file" can be present.

A metadata file is a text file and must be named metadata.txt (all lowercase).

Inside a metadata file, one can use the tag/value pairs described below.

Inside a metadata file, anything following the hash character (#) will be treated as a comment, i.e. ignored.

A tag is made by a reserved word (see below), followed by a colon, (optionally) a space, and any possible values, as described below.

Note that some of the tags (the ones with an asterisk) are mandatory for a metadata file placed inside a camera trap directory.

If need be, further tags can be defined.

Tag	Context	Description	Values
*`make`:	[C]	Make of the camera trap	Please use consistent naming and spelling
*`model`:	[C]	Model of the camera trap	Please use consistent naming and spelling
*`serial`:	[C]	Serial number of the camera trap	Please transcribe the exact serial number
*`lat`:	[C]	Camera position, latitude	Use raw latitude in decimal degrees, WGS84 (i.e. EPSG:4326)
*`lon`:	[C]	Camera position, longitude	Use raw longitude in decimal degrees, WGS84 (i.e. EPSG:4326)
`timezone`:	[C]	Time zone of camera position	Use time Olson/IANA zone name [1] as from R OlsonNames() function
*`start`:	[C]	Camera start timestamp	Use date and time expressed in ISO 8601 format [2]
*`end`:	[C]	Camera end timestamp	Use date and time expressed in ISO 8601 format [2]
`height`:	[C]	Camera ground height	Height from ground at which the camera treap has been placed
`aspect`:	[C]	Camera lens aspect	Aspect (in degrees, 0 to 360) at which the camera lens was facing
`placed`:	[C]	Who placed the camera	First name, last name
`removed`:	[C]	Who removed the camera	First name, last name
`name`:	[CS]	Site or Camera name	Please use consistent naming and spelling

*: the tag is mandatory.

S: tag is recognized for “sites”, ignored otherwise.

C: tag is recognized for “cameras”, ignored otherwise.

[1] Olson/IANA time zones and time zone names can be found at https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

[2] Dates and time must be expressed according to the ISO 8601 standard (UNI EN 28601, 1993), as follows: yyyy-MM-ddTHH:mm:ssK
where:

`yyyy`	year as four-digits number.
`MM`	month as two-digits number.
`dd`	day of month as two-digits number.
`HH`	hour, 24-hour format, as two-digits number.
`mm`	minutes as two-digits number.
`ss`	seconds (or '`00`' if exact seconds unknown) as two-digits number.
`K`	time zone offset, expressed as `=hh:mm` where "`=`" is either "`+`" or "`-`", "`hh`" is the hour offset and "`mm`" is the minutes offset (usually '`00`'). Use the '`Z`' (Zulu time) designator if and only if timestamps are actually in Zulu (UTC) time. If no offset is specified, the `timezone` key will be used, if the `timezone` key is not present, a lookup on web services will be attempted to identify the timezone from latitude and longitude.