The 1987 Field Representative's Manual instructed interviewers to probe to determine the best approximate values. For example, if the respondent reported, "on and off for 20 years," interviewers would probe to determine the total number of years, excluding the off periods. In 1992, the Manual instructed interviewers to record the verbatim response if the respondent reported a fraction.

The term "snuff" was respondent defined. The 1987 Field Representative's Manual defined snuff as, "a smokeless tobacco product that is either inhaled through the nostrils or placed in the mouth between the cheeks and gum or under the tongue. A common term for snuff use is "dipping." It added that this definition was for the interviewer's information only, and the term snuff should only be defined for the respondent if questioned. It also instructed interviewers to record, "DK Snuff" if the respondent reported they did not know what snuff was and to accept other brands of snuff as well as those given as examples.

Similar to 1987, the 1992 Manual mention that using snuff includes sniffing it or just placing it in the mouth.