Limits, A Few Minor Ones

The following limits apply.

There must not be any ASCII TAB characters in the data. This is the primary limit as the ASCII TAB character is the delimiter in rdbtables.
There must not be any pipe characters `|` used or entered as data when using the operator 'etbl'.
All of the Compare operators and Logical constructors are reserved and should not be used as column names (they are all lower case and four characters or less). They are: 'gt', 'ge', 'lt', 'le', 'eq', 'ne', 'or', 'and', 'null', 'mat', and 'nmat'.