as_factor               Convert input to a factor.
labelled                Create a labelled vector.
labelled_spss           Labelled vectors for SPSS
print_labels            Print the labels of a labelled vector
read_dta                Read and write Stata DTA files.
read_sas                Read and write SAS files.
read_spss               Read SPSS (SAV & POR) files. Write SAV files.
tagged_na               "Tagged" missing values
zap_empty               Convert empty strings into missing values.
zap_formats             Remove format attributes
zap_labels              Zap labels
zap_missing             Zap special missings to regular R missings
