Heian period
Poetry, in particular, was a staple of court life. Nobles and ladies-in-waiting were expected to be well versed in the art of writing poetry as a mark of their status. Every occasion could call for the writing of a verse, from the birth of a child to the coronation of an emperor, or even a pretty scene of nature. A well-written poem or haiku could easily make or break one's reputation, and often was a key part of social interaction.Almost as important was the choice of calligraphy, or handwriting, used. The Japanese of this period believed handwriting could reflect the condition of a person's soul: therefore, poor or hasty writing could be considered a sign of poor breeding. Whether the script was Chinese or Japanese, good writing and artistic skill was paramount to social reputation when it came to poetry. Sei Shonagon mentions in her Pillow Book that when a certain courtesan tried to ask her advice about how to write a poem to the empress Sadako, she had to politely rebuke him because his writing was so poor.

Q: What was said to show low status or "poor breeding"?
poor or hasty writing