An 'A' in a heart is a symbol of relationship anarchy.
Relationship anarchy (abbreviated RA) is the practice of forming relationships that are not bound by set rules. It differs from polyamory by postulating that there need not be a formal distinction between different types of relationships. Relationship anarchists look at each relationship (romantic or otherwise) individually, as opposed to categorizing them according to societal norms such as 'just friends', 'in a relationship', 'in an open relationship', etc. The term 'relationship anarchy' was coined by Andie Nordgren, and is the topic of Swedish bachelor theses by Jacob Strandell and Ida Midnattssol. It was discussed in workshops at OpenCon 2010, and by Senior Open University lecturer Dr Meg Barker in a presentation in 2013.
Relationship anarchs (or RAs) prefer not to divide relationships into subsets of those involving partners and those that do not, but instead have a more flexible approach in which everything is allowed by mutual agreement. RA is closely related to polyamory, and many relationship anarchists have multiple sexual, loving, or intimate relationships. One notable difference between polyamory and RA is the categorical distinction often (but not always) made by polyamorists regarding romantic relationships and friendships. In general, relationship anarchists tend not to recognize any such categorization, nor any conventional path to follow, in order to pursue, have, or express love in their relationships.