http://en.wikipedia.org/wiki/Radian
...
The radian is represented by the symbol rad (Unicode-encoded as U+33AD ㎭ ). An alternative symbol is the superscript letter c, for "circular measure"—but this is infrequently used as it can be easily mistaken for a degree symbol (°). So for example, a value of 1.2 radians could be written as 1.2 rad, 1.2rad, or 1.2c.
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Quote Alan: I'm much more used to assuming that radians are meant unless the degree symbol is used. ...
Engineers are used to Radians.
Side note: Most calculators are 10 times more precise (including this site) when trig functions are preformed in degrees instead of radians. If you need high precision, converting as needed is an optimal decision.
~~D~~
The following site lists countries by their number format system
www.codeproject.com/Articles/78175/International-Number-Formats
(The list is recent and comprehensive)
These formats are the most common
1,234.56
1.234,56
1'234.56
1 234,56
These formats are rare, used by one or two countries.
1,234/56
1 234-56
1 234.56
---- Note: Some multicultural countries use more than one format. It is probable that cross-cultural communications are sent in the recipient’s format, for clarity. Computer communications may automatically convert to recipient’s format via computer settings. ~~D~~