| unAnonymise | Data.GraphViz.Types, Data.GraphViz |
| Underline | |
| 1 (Data Constructor) | Data.GraphViz.Attributes.HTML |
| 2 (Data Constructor) | Data.GraphViz.Attributes.Complete, Data.GraphViz.Attributes, Data.GraphViz |
| undirCommand | Data.GraphViz.Commands, Data.GraphViz |
| UniformScale | Data.GraphViz.Attributes.Complete |
| UnknownAttribute | Data.GraphViz.Attributes.Complete |
| unqtDot | Data.GraphViz.Printing, Data.GraphViz.Types, Data.GraphViz |
| unqtEscaped | Data.GraphViz.Printing |
| unqtListToDot | Data.GraphViz.Printing, Data.GraphViz.Types, Data.GraphViz |
| unqtText | Data.GraphViz.Printing |
| unsafeFromCanonical | Data.GraphViz.Types.Graph |
| unwrapArrow | Data.GraphViz.Parsing |
| unwrapMonad | Data.GraphViz.Parsing |
| upto | Data.GraphViz.Parsing |
| URL | Data.GraphViz.Attributes.Complete |
| usedByClusters | Data.GraphViz.Attributes.Complete |
| usedByEdges | Data.GraphViz.Attributes.Complete |
| usedByGraphs | Data.GraphViz.Attributes.Complete |
| usedByNodes | Data.GraphViz.Attributes.Complete |
| usedBySubGraphs | Data.GraphViz.Attributes.Complete |
| UTR | Data.GraphViz.Attributes.Complete, Data.GraphViz.Attributes, Data.GraphViz |