Inviting brāhmaṇas for partaking the food during a śrāddha ceremony is an important part of that ritual. The dharma-śāstras prescribe elaborate rules with regard to the type of brāhmaṇas to be invited and also the mode of inviting them.
The two words constantly used in this connection are ‘āmantraṇa’ and ‘nimantraṇa.’ Though they are often used synonymously, subtle distinctions are sometimes made. A ‘nimantraṇa’ is more or less compulsory to accept. If the invitee rejects it without proper grounds, he is said to incur sin. But ‘āmantraṇa’ does not imply compulsion. The invitee has much greater freedom to accept or reject it.