diff --git a/README.md b/README.md
index 8d9c3ea..e6a6f5f 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,88 @@
 # archivist-utilities
-Tools for users of archivist
+
+This is a tool that implements the functionality described at https://ucldata.atlassian.net/wiki/spaces/CLOS/pages/37323492/Using+Txt+Files
+
+The tool is accessible at https://closer-cohorts.github.io/archivist-utilities/
+
+It accepts as input an Excel file (.xlsx)
+
+The worksheet containing data from which the qv, tv and tq mappings are created MUST be the first worksheet in the file. This worksheet can have any name.
+
+The worksheet containing data from which the dv mappings are created MUST be the second worksheet in the file. This worksheet can have any name.
+
+# QV mappings file
+
+The following column headers must be present in the first worksheet in the input Excel file, in order to create the qv text files:
+
+ - Questionnaire prefix
+ - Question name
+ - Dataset prefix
+ - Variable name
+
+The headers are not case sensitive, i.e. a column called 'question name' instead of 'Question Name' is acceptable.
+
+A separate qv text file will be created for each unique questionnaire prefix value in the first worksheet in the input Excel file.
+
+For example, if some rows in the input worksheet had the value 'heaf_17_fup4' for the 'Questionnaire prefix' column, and some other rows had the value 'heaf_17_fup5' for that column, this would result in 2 text files being generated: 
+ 
+ - heaf_17_fup4_qv.txt (containing all the rows which had the value 'heaf_17_fup4' in the 'Questionnaire prefix' column)
+ - heaf_17_fup5_qv.txt (containing all the rows which had the value 'heaf_17_fup5' in the 'Questionnaire prefix' column)
+
+# TV mappings file
+
+The following column headers must be present in the first worksheet in the input Excel file, in order to create the tv text files:
+
+ - Dataset prefix
+ - Variable name
+ - Topic id
+
+The headers are not case sensitive, i.e. a column called 'dataset prefix' instead of 'Dataset Prefix' is acceptable.
+
+A separate tv text file will be created for each unique dataset prefix value in the input Excel file.
+
+For example, if some rows in the input worksheet had the value 'heaf_17_fup4' for the 'Dataset prefix' column, and some other rows had the value 'heaf_17_fup5' for that column, this would result in 2 text files being generated: 
+ 
+ - heaf_17_fup4_tv.txt (containing all the rows which had the value 'heaf_17_fup4' in the 'Dataset prefix' column)
+ - heaf_17_fup5_tv.txt (containing all the rows which had the value 'heaf_17_fup5' in the 'Dataset prefix' column)
+ 
+# TQ mappings file
+
+The following column headers must be present in the first worksheet in the input Excel file, in order to create the tq text files:
+
+ - Questionnaire prefix
+ - Question name
+ - Topic id
+
+The headers are not case sensitive, i.e. a column called 'question name' instead of 'Question Name' is acceptable.
+
+A separate tq text file will be created for each unique questionnaire prefix value in the input Excel file.
+
+For example, if some rows in the input worksheet had the value 'heaf_17_fup4' for the 'Questionnaire prefix' column, and some other rows had the value 'heaf_17_fup5' for that column, this would result in 2 text files being generated: 
+ 
+ - heaf_17_fup4_tq.txt (containing all the rows which had the value 'heaf_17_fup4' in the 'Questionnaire prefix' column)
+ - heaf_17_fup5_tq.txt (containing all the rows which had the value 'heaf_17_fup5' in the 'Questionnaire prefix' column)
+ 
+# DV mappings file
+
+The following column headers must be present in the first worksheet in the input Excel file, in order to create the dv text files:
+
+ - Dataset prefix
+ - Derived variable name
+ - Source variable name
+
+The headers are not case sensitive, i.e. a column called 'dataset prefix' instead of 'Dataset Prefix' is acceptable.
+
+A separate dv text file will be created for each unique dataset prefix value in the input Excel file.
+
+For example, if some rows in the input worksheet had the value 'heaf_17_fup4' for the 'Dataset prefix' column, and some other rows had the value 'heaf_17_fup5' for that column, this would result in 2 text files being generated: 
+ 
+ - heaf_17_fup4_dv.txt (containing all the rows which had the value 'heaf_17_fup4' in the 'Dataset prefix' column)
+ - heaf_17_fup5_dv.txt (containing all the rows which had the value 'heaf_17_fup5' in the 'Dataset prefix' column)
+          
+# Text mapping file generation
+
+To generate the text mapping files for Archivist from an Excel XLSX file, simply:
+
+1. Select the Excel XLSX file from your local computer by pressing the 'Choose file' button
+2. A 'Convert file' button will appear after you have selected an XLSX file. Press this button.
+3. Links to the various text files generated from this XLSX file will now displayed on the screen, and clicking on these will download the text files to your local computer.
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diff --git a/index.html b/index.html
index bc98f14..39551d8 100644
--- a/index.html
+++ b/index.html
@@ -38,10 +38,10 @@ <h1>Generate text mappings files</h1>
 
     }
 
-    function createBlobURL(worksheetDataByRows, columns, suffix = {}) {
-
-      var fileData = ""
+    function columnNamesToLowerCase(worksheetDataByRows) {
 
+      const rowValues = []
+        
       worksheetDataByRows.forEach(worksheetRow => {
 
         // We need to create a new object to hold the row data so we can ensure the
@@ -51,9 +51,23 @@ <h1>Generate text mappings files</h1>
 
         Object.keys(worksheetRow).forEach(fieldName => rowData[fieldName.toLowerCase()] = worksheetRow[fieldName])
 
+        rowValues.push(rowData)
+
+      })
+
+      return rowValues
+
+    }
+
+    function createBlobURL(worksheetDataByRows, columns, suffix = {}) {
+
+      var fileData = ""
+
+      worksheetDataByRows.forEach(worksheetRow => {
+
         const rowValues = []
         
-        columns.map(columnName => rowValues.push(rowData[columnName.toLowerCase()] 
+        columns.map(columnName => rowValues.push(worksheetRow[columnName.toLowerCase()] 
           + (!!suffix[columnName] ? suffix[columnName] : "")))
 
         if (!(rowValues.includes("NA") || rowValues.includes("Derived") || rowValues.includes("")))
@@ -108,16 +122,17 @@ <h1>Generate text mappings files</h1>
         
         const qvTvWorksheet = wb['Sheets'][Object.keys(wb['Sheets'])[0]]
 
-        const qvTvWorksheetOrderedByRows = XLSX.utils.sheet_to_json(qvTvWorksheet, { defval: "" });
+        const qvTvWorksheetOrderedByRows = columnNamesToLowerCase(
+          XLSX.utils.sheet_to_json(qvTvWorksheet, { defval: "" }))
 
         var datasetPrefixes = (getUniqueArrayValues(qvTvWorksheetOrderedByRows.map(
-          worksheetRow => worksheetRow['Dataset prefix']).filter(datasetPrefixCell =>
+          worksheetRow => worksheetRow['dataset prefix']).filter(datasetPrefixCell =>
             (!!datasetPrefixCell && !(datasetPrefixCell.includes("NA") 
             || datasetPrefixCell.includes("Derived") || !datasetPrefixCell))
         )))
 
         var questionnairePrefixes = (getUniqueArrayValues(qvTvWorksheetOrderedByRows.map(
-          worksheetRow => worksheetRow['Questionnaire prefix']).filter(questionnairePrefixCell =>
+          worksheetRow => worksheetRow['questionnaire prefix']).filter(questionnairePrefixCell =>
             (!!questionnairePrefixCell && !(questionnairePrefixCell.includes("NA") 
             || questionnairePrefixCell.includes("Derived") || !questionnairePrefixCell))
         )))
@@ -125,9 +140,9 @@ <h1>Generate text mappings files</h1>
         questionnairePrefixes.forEach(questionnairePrefix => {
           
           var qvLinkURL = createBlobURL(qvTvWorksheetOrderedByRows.filter(
-            worksheetRow => worksheetRow['Questionnaire prefix'] == questionnairePrefix), 
-              ['Questionnaire prefix', 'Question Name', 'Dataset prefix', 'Variable Name'],
-              { 'Questionnaire prefix': '_ccs01' })
+            worksheetRow => worksheetRow['questionnaire prefix'] == questionnairePrefix), 
+              ['questionnaire prefix', 'question name', 'dataset prefix', 'variable name'],
+              { 'questionnaire prefix': '_ccs01' })
 
             addLinkToPage(qvLinkURL, 
             `${questionnairePrefix}_qv.txt`, 
@@ -139,8 +154,8 @@ <h1>Generate text mappings files</h1>
         datasetPrefixes.forEach(datasetPrefix => {
           
           var tvLinkURL = createBlobURL(qvTvWorksheetOrderedByRows.filter(
-            worksheetRow => worksheetRow['Dataset prefix'] == datasetPrefix), 
-            ['Dataset prefix', 'Variable Name', 'Topic ID'])
+            worksheetRow => worksheetRow['dataset prefix'] == datasetPrefix), 
+            ['dataset prefix', 'variable name', 'topic id'])
           
           addLinkToPage(tvLinkURL, 
           `${datasetPrefix}_tv.txt`, 
@@ -152,22 +167,22 @@ <h1>Generate text mappings files</h1>
         simplifiedData = []
 
         qvTvWorksheetOrderedByRows.forEach(worksheetRow => {
-          if (worksheetRow['Question Name'].includes("$")) {
-            indexOfDollarSign = worksheetRow['Question Name'].indexOf("$")
-            worksheetRow['Question Name'] = (worksheetRow['Question Name'].slice(0, indexOfDollarSign))
+          if (worksheetRow['question name'].includes("$")) {
+            indexOfDollarSign = worksheetRow['question name'].indexOf("$")
+            worksheetRow['question name'] = (worksheetRow['question name'].slice(0, indexOfDollarSign))
 
           }
-          if (simplifiedData.filter(dataRow => dataRow['Question Name'] == worksheetRow['Question Name']
-            && dataRow['Topic ID'] == worksheetRow['Topic ID']).length == 0)
+          if (simplifiedData.filter(dataRow => dataRow['question name'] == worksheetRow['question name']
+            && dataRow['topic id'] == worksheetRow['topic id']).length == 0)
             simplifiedData.push(worksheetRow)
         })
         
         questionnairePrefixes.forEach(questionnairePrefix => {
           
           var tqLinkURL = createBlobURL(simplifiedData.filter(
-            dataRow => dataRow['Questionnaire prefix'] == questionnairePrefix), 
-            ['Questionnaire prefix', 'Question Name', 'Topic ID'],
-            { 'Questionnaire prefix': '_ccs01' })
+            dataRow => dataRow['questionnaire prefix'] == questionnairePrefix), 
+            ['questionnaire prefix', 'question name', 'topic id'],
+            { 'questionnaire prefix': '_ccs01' })
           
           addLinkToPage(tqLinkURL, 
             `${questionnairePrefix}_tq.txt`, 
@@ -180,20 +195,21 @@ <h1>Generate text mappings files</h1>
 
         const dvWorksheet = wb['Sheets'][Object.keys(wb['Sheets'])[1]]
 
-        const dvWorksheetOrderedByRows = XLSX.utils.sheet_to_json(dvWorksheet, { defval: "" });
+        const dvWorksheetOrderedByRows = columnNamesToLowerCase(
+          XLSX.utils.sheet_to_json(dvWorksheet, { defval: "" }))
 
         datasetPrefixes = (getUniqueArrayValues(dvWorksheetOrderedByRows.map(
-          worksheetRow => worksheetRow['Dataset prefix']).filter(datasetPrefixCell =>
+          worksheetRow => worksheetRow['dataset prefix']).filter(datasetPrefixCell =>
           (!!datasetPrefixCell 
           && !(datasetPrefixCell.includes("NA") || datasetPrefixCell.includes("Derived") || !datasetPrefixCell))
         )))
 
         datasetPrefixes.forEach(datasetPrefix => {
           var dvLinkURL = createBlobURL(dvWorksheetOrderedByRows.filter(
-            worksheetRow => worksheetRow['Dataset prefix'] == datasetPrefix), ["Dataset prefix",
-            "Derived Variable Name",
-            "Dataset prefix",
-            "Source Variable Name"
+            worksheetRow => worksheetRow['dataset prefix'] == datasetPrefix), ["dataset prefix",
+            "derived variable name",
+            "dataset prefix",
+            "source variable name"
           ])
           addLinkToPage(dvLinkURL, 
           `${datasetPrefix}_dv.txt`, 
@@ -209,7 +225,6 @@ <h1>Generate text mappings files</h1>
 
   </script>
 
-
 </body>
 
 </html>
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