[Include_Once] inserts the specified format file into the current format file. Any Lasso code in the included format file is executed as if were placed in the current format file at the location of the [Include_Once] tag.

The first parameter is the name of the format file to be included.

A boolean parameter -local optionally instructs Lasso to determine the file path relative to the current file.

If [Include_Once] is used multiple times referencing the same Lasso page then only the first [Include_Once] will actually perform the include. Subsequent [Include_Once] tags which reference the same file will do nothing.

See [include] for more detail.