India, Sept. 14 -- In 1974, while completing her postgraduate engineering studies at the Indian Institute of Science, Sudha Murty saw a recruitment notice from TELCO, now Tata Motors. It sought bright young engineers but ended with five blunt words: "Lady candidates need not apply."

Murty wrote directly to JRD Tata. She was invited to Pune for an interview and went on to become TELCO's first woman engineer. Her education had given her the qualification. It had not given her an ordinary route into the profession. A postcard had to open that door.

Five decades later, the barrier is less likely to be printed at the bottom of an advertisement. It is more likely to be hidden in the journey home, the project group, the professional network or...