The edited variables for the Work Schedule module whose names end with the suffix "1" (for example, EWSHRS1, EWSDY1, etc.), relate to the work schedule for the main job or business the person held in reference month 4. The edited variables for the Work Schedule module whose names end with the suffix "2" (for example, EWSHRS2, EWSDY2, etc.), relate to the work schedule for the second most important job or business the person held in reference month 4. The variables with suffix "1" are known as "job 1" variables; those with suffix "2" are called "job 2" variables.

The user is able to link the "job 1" and "job 2" variables with the information about the employers for these jobs in the Core section of the 2001 SIPP Wave 4 file by using the variables: EWSENO1, EWSENO2, EWSBNO1, EWSBNO2. A deterministic procedure to link the Core employer name with the job 1 and job 2 variables was erroneously omitted from the data collection instrument. As a consequence, a probabilistic linking procedure had to be applied in the post-collection edit. Accordingly, the user is cautioned that EWSENO1, EWSENO2, EWSBNO1, EWSBNO2, while reliable in the vast majority of instances, are not perfect. The user is especially cautioned that the job 1 and job 2 variables should not be linked backed to Core information for persons for whom EWSENO1=EWSENO2.