'Rhiannon' was produced by women who were part of the Women's Liberation Movement. Articles reflect the Movement's demands for equal pay and equal work, equal education and equal opportunities, free contraception and abortion on demand, free 24 hour community controlled childcare, legal and financial independence for women, an end to discrimination against lesbians, and freedom for all women from intimidation by the threat or use of violence and sexual coercion.
An attempt was made to include articles in Welsh in each issue and requests feature in every magazine for Welsh contributions or assistance with translation.
Cynhyrchwyd 'Rhiannon' gan fenywod a oedd yn rhan o Fudiad Rhyddhad Menywod. Mae'r erthyglau yn adlewyrchu gofynion y Mudiad am gyflog cyfartal a gwaith cyfartal, addysg cyfartal a chyfleoedd cyfartal, atalyddion cenhedlu am ddim ac erthyliad ar galw, gofal plant cymunedol 24 awr am ddim, annibyniaeth cyfreithiol ac ariannol ar gyfer menywod, diwedd ar anffafriaeth yn erbyn pobl lesbiaidd, a rhyddid i pob fenyw o fygythiad drwy bygwth neu defnyddio trais a gorfodaeth rhywiol.
Ceisiwyd cynnwys erthyglau yn y Gymraeg ym mhob rhifyn a cheir galw ym mhob cylchgrawn am gyfraniadau Cymraeg neu gymorth gyda gyfieithu.