I am trying to associate a .csvt file with a .csv file, so QGIS doesn't insist on calling all the fields text strings (thereby preventing the use of graduated symbols). I used the syntax described by other answers here and on other sites in the .csvt file, ie: "String","Integer","Integer" etc. I saved it in Text Editor on my Mac with the same name as the .csv file and in the same folder.
For whatever reason, QGIS is not recognizing the .csvt file's information and continues to deem every field of the .csv file a text string. I do not know if this is the fault of the Text Editor not recognizing the file format, or of QGIS not recognizing the .csvt when it ought to.
Anyone have troubleshooting ideas or work-arounds?