`$V{<alias>.<column>}` is replaced by one column of the row currently in hand within a repetition. The alias is the one given on the [[Possible instructions|foreach instruction]] which produced the row, and the column is one of the columns its query selected. A column which was not selected is not available: what is not in the query is not in the row. Within a repetition, `<invantive:value-of expression="$V{pjt.pjt_code}" />` and `<invantive:value-of querylabel="pjt" field="pjt_code" />` say the same thing. The alias is what makes nesting work. In the query of an inner repetition a value from the row of the outer one may be used, which is how the rows underneath are limited to the row above them: ``` <invantive:foreach alias="pjt" query="select pjt_code from projects_v"> <invantive:foreach alias="csc" query="select ccr_code from cost_centres_v where pjt_code = $V{pjt.pjt_code}"> ``` Outside the repetition which declared it, an alias no longer exists.