10375
On 28 April 2011 , Flattr announced by email that they would not require users to flattr others before they could be flattrd themselves , starting from 1 May 2011 .
 Flattr
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Flattr