This template returns {{{1}}} {{{2}}} if {{{2}}} is either not specified or set to AD. Otherwise it returns {{{1}}} {{{2}}} or,
iff{{{3}}} is specified, {{{1}}} {{{3}}}.
Examples
1
{{Decades and years/addepoch|1|BC}} 1 BC
{{Decades and years/addepoch|1|AD}} 1
{{Decades and years/addepoch|1|BC|<small>BC</small>}} 1 BC
{{Decades and years/addepoch|1|AD|<small>BC</small>}} 1
0s
{{Decades and years/addepoch|0s|BC}} 0s BC
{{Decades and years/addepoch|0s|AD}} 0s
{{Decades and years/addepoch|0s|BC|<small>BC</small>}} 0s BC
{{Decades and years/addepoch|0s|AD|<small>AD</small>}} 0s