It's a slightly curious expression because mandatory or compulsory means that it's an obligation, but to say that a mandatory gala dinner is included in the the rate means, without a doubt, the price you have paid for your hotel room for example includes (i.e. free) the dinner. So to conclude it means that a gala dinner is included in the price you paid.
Gala Dinner means a special dinner
A Gala Dinner in Hindi can be called "गाला डिनर" (Gala Dinar) or "उत्सव डिनर" (Utsav Dinar).
The dress code for a gala dinner is a jacket And Black tie. wed-shopping.com
An annual dinner is commonly referred to as a gala or banquet.
Gala dinner - A private room reserved for a group to pre order off a set menu and seated in banquet or cabaret style sometimes with dance floor and room for a stage, entertainments etc.
Griechenbeisl
carnival, festival, dinner, gala, treat, picnic
When you are going to a gala you need to dress formal. For many galas the dress code is black tie.
For a gala dinner you dress with a fancy dress. Mostly solid colors like Dark red, or black. For shoes just wear black high heels with a little design on it.
a thong :)
A gala, sometimes referred to as a festival, is a celebration within a community that often involves a sit-down dinner in banquet style. There may be musical entertainment, dancing, speeches, or stage performances.
We return to lorraine for our farewell gala dinner.