The Occupation 'Title' field (a.k.a. occupation/profession/job title) should contain the tag and qualifier and an optional qualifier prefix as follows
The Occupation 'Company' field (a.k.a. Company/Employer/Organisation) should contain any Gedcom Agency (AGNC tag) value and optionally a narrative prefix.
Narrative phrases have been added to Dictionary.xml to report on these additional values in an Evednts & Attributes sub-section on the individual's or family's page.
See the Individual 'Jed Com' in the report
http://familytrees.genopro.com/genome/gedcomtags/default.htm and note how the tags are reported in their own subsection and also on timelines and Google Map 'info' windows for places.
The .gno used can be downloaded from there if you wish to examine exactly how the data is recorded.
N.B. Most events are recorded as a single point in time rather than for a specific duration and therefore the start and end dates should have the same value.
Family events are recorded in a similar fashion but using Marriage/Union fields 'Witnesses' and 'Officiator' instead of Occupation Title and Company.
I did consider using Custom Tags but entering custom tag data for Unions can only be achieved via the Table Layout view which I thought was far to cumbersome.
The latest Narrative Report skin (2013.07.30) detects this special usage and reports accordingly.
The Export to Gedcom report skin (2013.xx.xx) will export this information under their original tags, not as Occupations and Marriages.
Of course Occupations and Unions still retain their original usage when no special tag format is used.