This function shows the spec underlying iCal files.
     
    
    ic_spec(mode = "view", spec_url = "https://tools.ietf.org/rfc/rfc5545.txt")
 
    
    Arguments
- mode
- character string specifying whether to look at the spec (- mode = "view", the default)
or read it in (- mode = "read")
 
- spec_url
- the location of the latest version of the spec, from
tools.ietf.org/rfc/rfc5545.txt by default