Just like the need for a flag to represent the whole of the Rainbow family there was, and still is a need to represent other parts of the LGBT Community with a symbol to stand under and be proud of representing all of the trans community.
The most popular in both USA and parts of Europe is this Transgender flag and was created by American Trans woman Monica Helms in 1999, first revealed at the Phoenix, Arizona pride parade in 2000. The flag represents the transgender community and consists of five horizontal stripes: two light blue, two pink, and one white in the centre.
Monica, the designer of this flag (above) explains its meaning “The stripes at the top and bottom are light blue, the traditional color for baby boys. The stripes next to them are pink, the traditional color for baby girls. The stripe in the middle is white, for those who are intersex, transitioning or consider themselves having a neutral or undefined gender. The pattern is such that no matter which way you fly it, it is always correct, signifying us finding correctness in our lives.
Other Transgender flags have been designed over the years, here are a few.
The above flag was created back in 2002 by Jennifer Pellinen. The top of the flag is pink and the colours descend down into the blue. It is said to represent the diversity of the transgender community.
The transgender community in Israel uses the above flag, using one of a few transgender symbols.
If you know anymore transgender signs and symbols, I am sure there are a few, let me know and I will look into them, in order to make a more comprehensive list.