Zahira, I am enclosing a few of the many stages of a hindu wedding in which the sindoor is the last stage after a ceremony and is defined as follows-
Suhaag or Sindhoordana
The groom places sindhoor (red powder) on the bride's hair symbolizing her as a married woman.
Few of the Stages of a marriage ceremony
Kanya Danam (Giving away of the daughter)
The bride accepts her change of status from an unmarried woman to a wife by spreading turmeric powder on her hands.
Kana Danam is performed by the father (or uncle of guardian) of the bride in presence of a large gathering that is invited to witness the wedding.
Vivaaha (Wedding)
The bride and the bridegroom face each other, and the priest ties their garments (the bride's saree to the groom's shirt) in a knot, symbolizing the sacred union.
The bride and the bridegroom garland each other and exchange the rings.
Next the nuptial fire, symbolizing the divine witness, and the sanctifier of the sacrament, is installed and worshipped.
Agni Parinaya : The Circumambulation of the Fire
The bridegroom holds the bride by the hand and both walk three times around the nuptial fire.
Both offer oblations and recite appropriate Vedic hymns to Gods for prosperity, good fortune, and conjugal fidelity.
They touch each others heart and pray for union of their hearts and minds
Asmaarohana or Shilarohana (Mounting the stone)
At the end of each round of nuptial fire, both the bride and the groom step on a stone and offer a prayer for their mutual love to be firm and steadfast like the stone.
Satapadi (Seven Steps)
This is the most important rite of the entire ceremony. Here the bride and the bridegroom take seven steps together around teh nuptial fire (Agni) and make the following seven promises to each other :
As per the Vedic rituals, the bridegroom sings the following :
With God as our guide, let us take :
the first step to nourish each other
the second step to grow together in strength
the third step to preserve our wealth
the fourth step to share our joys and sorrows
the fifth step to care for our children
the sixth step to be together forever
the seventh step to remain lifelong friends,
the perfect halves to make a perfect whole.
After the seventh step he makes her remain where she is and says:
"With seven steps we become friends. Let me reach your friendship. Let me not be severed from your friendship. Let your friendship not be severed from me."
The Saptapadi ceremony concludes with a prayer that the union is indissoluble. At the end of this ceremony, the bridegroom and bride become husband and wife.
Mangal Sutra Dharana
The Mangala suthra Dharana is the tying of the thread with gods symbols symbolizing marriage and the shloka means -
Meaning: This is a sacred thread, this is essential for my long life. I tie this around your neck
O maiden, having many auspicious attributes, may you live happily for a hundred years
Suhaag or Sindhoordana
The groom places sindhoor (red powder) on the bride's hair symbolizing her as a married woman.
Aashirvaad
The groom's parents bless the couple and offer cloth or flower to the bride (now their daugher-in-law), symbolizing her joining of the groom's family.
All those assembled shower flowers on the couple and bless them completing the marriage.
****************
Therefore guys merely putting sindoor is on a girls forehead is not indicative of a marriage - its a symbol as the mangalsutra
**PD**