Most commands in MODELLER take one or more keyword arguments. The valid keywords are listed, one per line, after each command. For convenience, many of these keywords take a default value if you not specify them. These default values themselves are stored in the environ class, so that you can specify global defaults (see section 6.2).
MODELLER will report an error if you do not specify a keyword which does not have a default.
Each keyword argument must be of a specific type, either a MODELLER class object (e.g., a model or alignment) or one of the standard types shown below:
| <int:1> | an integer variable or constant |
| <float:1> | a floating-point variable or constant |
| <str:1> | a string variable or constant |
| <bool:1> | a boolean variable or constant |
| <int:0> | a tuple of any length with elements <int:1> |
| <int:N> | a tuple of 
elements <int:1> |
| etc. | the same for float, str, and bool types |