Anyone performing the data entry will have the same understanding of what the variables mean, and what kinds of data are being collected. Precoding can be done in Epi Info with the development of a Check file. The Check file will suffice as a Codebook for the required documentation. If you are not using Epi Info, then you must create a Codebook listing all your variables and the data you have collected for each variable. If you are using a statistical program that can only analyze numeric data, you must define what the numeric codes mean in the Codebook.
Many statistical programs can only process numeric data.
Additionally, when reporting, you would have to convert your numeric codes to character data anyway. For each data collection instrument, include a Codebook in the Appendix. You would first record the statements as reported, using a word processor, in a word processing document. Then you would develop codelists in which you show how you categorized all the responses. These categories would be a derived variable that you would then analyze.