as_ddi                  Convert XML trees to DDI objects
as_xml                  Get XML representation of ddi_node objects
as_xml_string           Shortcut to text representation of DDI XML
ddi_anlyInfo            anlyInfo and its child nodes
ddi_anlysUnit           anlysUnit node
ddi_boundPoly           boundPoly and its child nodes
ddi_catgry              catgry, catgryGrp and their child nodes
ddi_citation            citation, sourceCitation, fileCitation and
                        their child nodes
ddi_codeBook            Codebook
ddi_codingInstructions
                        codingInstructions and its child nodes
ddi_cohort              cohort and its child nodes
ddi_concept             concept node
ddi_contact             contact node
ddi_controlledVocabUsed
                        controlledVocabUsed and its child nodes
ddi_dataAccs            dataAccs and its children
ddi_dataColl            dataColl and its children
ddi_dataDscr            dataDscr and its children
ddi_dataFingerprint     dataFingerprint and its child nodes
ddi_dataItem            dataItem and its child nodes
ddi_dataSrc             dataSrc node
ddi_derivation          derivation and its child nodes
ddi_developmentActivity
                        developmentActivity and its child nodes
ddi_dimensns            dimensns, recDimnsn and their child nodes
ddi_distStmt            ddi_distStmt and its children
ddi_dmns                dmns and its child nodes
ddi_docDscr             docDscr and its children
ddi_docSrc              docSrc and its child nodes
ddi_embargo             embargo node
ddi_exPostEvaluation    exPostEvaluation and its child nodes
ddi_fileDscr            fileDscr and its children
ddi_fileStrc            fileStrc and its child nodes
ddi_fileTxt             fileTxt and its children
ddi_frameUnit           frameUnit and its children
ddi_geoBndBox           geoBndBox and its child nodes
ddi_imputation          imputation node
ddi_labl                labl node
ddi_locMap              locMap and its child nodes
ddi_location            location node
ddi_method              method and its child nodes
ddi_mrow                mrow and its child nodes
ddi_nCube               nCube and its child nodes
ddi_nCubeGrp            nCubeGrp and its child nodes
ddi_notes               notes node
ddi_otherMat            otherMat and its children
ddi_othrStdyMat         othrStdyMat and its child nodes
ddi_point               point and its child nodes
ddi_polygon             polygon and its child nodes
ddi_prodStmt            prodStmt and its child nodes
ddi_producer            producer node
ddi_qstn                qstn and its child nodes
ddi_qualityStatement    qualityStatement and its child nodes
ddi_range               range node
ddi_recGrp              recGrp and its child nodes
ddi_resource            resource and its child nodes
ddi_respUnit            respUnit node
ddi_row                 row and its child nodes
ddi_rspStmt             rspStmt and its child nodes
ddi_sampleFrame         sampleFrame and its children
ddi_security            security node
ddi_serStmt             serStmt and its child nodes
ddi_setAvail            setAvail and its children
ddi_sources             sources and its child nodes
ddi_srcChar             srcChar node
ddi_srcDocu             srcDocu node
ddi_srcOrig             srcOrig documentation
ddi_standard            standard and its child nodes
ddi_standardsCompliance
                        standardsCompliance and its child nodes
ddi_stdyDscr            stdyDscr and its children
ddi_stdyInfo            stdyInfo and its child nodes
ddi_studyAuthorization
                        studyAuthorization and its child nodes
ddi_studyDevelopment    studyDevelopment and its child nodes
ddi_subject             subject and its child nodes
ddi_sumDscr             sumDscr and its child nodes
ddi_table               table and its child nodes
ddi_targetSampleSize    targetSampleSize and its children nodes
ddi_tbody               tbody and its child nodes
ddi_tgroup              tgroup and its child nodes
ddi_thead               thead and its child nodes
ddi_titl                titl node
ddi_titlStmt            titlStmt and its child nodes
ddi_txt                 txt node
ddi_universe            universe node
ddi_usage               usage and its child nodes
ddi_useStmt             useStmt and its children
ddi_valrng              valrng, invalrng, and their child nodes
ddi_var                 var and its child nodes
ddi_varGrp              varGrp and its child nodes
ddi_verStmt             verStmt and its child nodes
validate_codebook       Validate generated codebook against DDI
                        Codebook 2.5
