InfoVeg

SQL to accomplish that:
SELECT project.projectName, project.entry_projectCode AS [project Code], observation.authorObsCode AS obsCode, observation.authorPlotCode AS plotCode_entry, plot.authorPlotCode AS plotcode_archive, IIf(startsWith([observation].[authorObsCode],[entry_projectCode] & "-") And startsWith([observation].[authorPlotCode],[entry_projectCode] & "-") And startsWith(nz([plot].[authorPlotCode],[entry_projectCode] & "-"),[entry_projectCode] & "-"),True,False) AS allOK
FROM (observation LEFT JOIN plot ON observation.PLOT_ID = plot.PLOT_ID) LEFT JOIN project ON observation.PROJECT_ID = project.PROJECT_ID;