i have several variables that i want to rename according to their category for example S2_Q1P- S2_Q7P would be plot and i want to rename them in a sequence such that the result is S2_Q1P_1- S2_Q7P_9.. I use the following code and i get the message

1 new variable name invalid
You attempted to rename S2_Q1K to 1. That is an invalid Stata variable name.



forval i=1/9 {
rename S2_Q1K `i' S2_Q1P `i' S2_Q1D `i'
rename S2_Q2AK`i' S2_Q2AP`i' S2_Q2AD`i'
rename S2_Q2BK`i' S2_Q2BP`i' S2_Q2BD`i'
rename S2_Q3AK`i' S2_Q3AP`i' S2_Q3AD`i'
rename S2_Q3BK `i' S2_Q3BP `i' S2_Q3BD `i'
rename S2_Q4K `i' S2_Q4P `i' S2_Q4D `i'
rename S2_Q5K `i' S2_Q5P `i' S2_Q5D `i'
rename S2_Q6K `i' S2_Q6P `i' S2_Q6D `i'
rename S2_Q7K `i' S2_Q7P `i' S2_Q7D `i'
}

i am renaming then in order to reshape such that corresponding questions align with the category name. should i use foreach v in varlist instead but how would i rename all of them in the simplest way possible? or is it not necessary for me to rename at all? I am very confused, earlier i had used forval i=1/9 to rename S2_Q2_01 and it had worked at that time. thank you for all the help i really appreciate it.