ft</dt>
<dd><p>What to do if the left table doesn't contain
all key combinations</p></dd>


<dt>missing_key_combination_right</dt>
<dd><p>What to do if the right table doesn't contain
all key combinations</p></dd>


<dt>inconsistent_factor_levels</dt>
<dd><p>What to do if the key columns from both sides
have inconsistent factor levels</p></dd>


<dt>inconsistent_type</dt>
<dd><p>What to do if we joined keys have a different type</p></dd>


<dt>grouped_input</dt>
<dd><p>What to do if one or both of the table