Variable V022 is at individual level, HV022 is at household level, but the two variables have the same contents. In older survey data sets, HV022/V022 might be codes for the paired clusters used for sampling error calculation, even the label of the variable is sampling stratum. Checking the frequency of the variable will help you understand if it is paired clusters (HV022/V022 has a large number of categories) or not. In recent surveys, HV022/V022 is labeled as "sample strata used for sampling errors", it is actually the sampling stratum used in sample selection. Another variable HV023/V023 is labeled as "sample strata used for sample selection", it is actually the same thing as HV022/V022 without exception. It might be the case that not all of the two variables are coded, use the one which is coded. Again, you can check the frequency of the variable. In any case, if you use HV025/V025 crossing HV024/V024, you will get the correct stratification in most of the cases, or it is close enough to the true stratification which will be good enough for all analysis purposes where stratification information is requested.