What are the various Informix column data types?

I am writing a query where I need to know if a column is of the "BLOB" type of column. According to this documentation 41 is the number for "BLOB" types of columns, in general. However, when I query the syscolumns table I see that columns, which store BLOB data, actually have values of 297, in my case. That page linked above does not even have number "297" anywhere on its page. I found another page, titled "Data Type Constants" but here again, number "297" is not even present anywhere on the page. It appears that documentation's list of data types is not complete. Is there a (more) complete list of column types in Informix?