p ralloc module to design randomized controlled trials
p ranova module to estimate single factor repeated measures ANOVA
p ranvar module to compute the random group variance estimator of the mean for survey data
p raschcvt module to produce data in WINSTEPS format
p rdplot module to graph residual distribution after regression-type command
p readlog module to read and process a file
p recast2 module to change storage type of variable
p recode2 module to provide extended recode capabilities
p reformat module to reformat regression output
p reg3 modules to perform three-stage least squares and SURE (version 5)
p regdplot module to produce regression diagnostics plot
p reglike module to calculate log-likelihood function value from regress
p regplot module to plot regression fit 
p regpred module to calculate linear regression predictions
p regresby module to generate regression residuals by byvarlist
p renames module to rename variables
p rensfix module to rename variable and change suffix
p reshape7 module to provide improved reshape
p rfregk module to estimate random-effects model with weights
p rglm module to estimate robust generalized linear models
p rgroup module for Random Group Variance Estimation
p rhetplot module to graph residual heteroscedasticity after regression-type command
p rmanova module to estimate repeated measures ANOVA
p rnd modules for random number generation
p roblpr module to estimate long memory in a set of timeseries
p rowranks module to create row ranks of a set of variables 
p rowsort module to row sort a set of integer variables
p russ_stata tutorial in Russian
p rvfplot2 module to produce residual-versus-fitted plot after regression-type command
p rvlrplot module to plot residuals vs lagged residuals for time series data
p rvpplot2 module to graph residual-versus-predictor plot after regression-type command