Androgen Resistance or Androgen Insensitivity Syndrome is a rare intersex trait affecting 1/20,000 to 1/64,000 AMAB or otherwise CTM individuals, causing one to be more resistant to androgens (such as testosterone.)
Depending on the severity of the traits, they may also fall under aromatase excess syndrome.
Complete Androgen Insensitivity Syndrome
Complete Androgen Insensitivity Syndrome (CAIS) is a subset of this variation, in which one with XY chromosomes has a complete inability for the cells to respond to androgen receptors. Those with CAIS look outwardly mullerian, with a vagina and breasts. They may have underdeveloped labia and/or clitoral hypoplasia. They have testicles that are either within the labia or within the inguinal ring.
Most do not have a uterus, cervix, or fallopian tubes, however in rare cases it does occur.
Partial Androgen Insensitivity Syndrome
Partial Androgen Insensitivity Syndrome (PAIS) is a subset of this variation, in which one with XY chromosomes has a partial inability of the cell to respond to androgen receptors. Those with PAIS have a penis (possibly with hypospadias, chordee, and/or a bifid scrotum), micropenis, clitoromegaly, or ambiguous genitalia. Those with PAIS have testicles, with cryptorchidism being common. Some also experience mild breast growth. 
Mild Androgen Insensitivity Syndrome
Mild Androgen Insensitivity Syndrome (MAIS) is a subset of this variation, in which one with XY chromosomes has a mild inability for the cells to respond to androgen receptors. Those with MAIS appear mostly wolffian, with a penis (sometimes with hypospadias) or micropenis. Some also experience mild breast growth. Those with this variation are infertile and will not develop many secondary sex traits, however this is typically reversable through testosterone supplements (HRT.)
The flag was coined by Pride-Flags on Deviantart, along with an anomynous user. It is made to resemble an orchid, as an orchid is a common symbol for intersex individuals.