Short sender. It is called a "short code" when it is between 3 and 6 digits long. These numbers indicate that the provider or company is using an A2P service and not SIMS or regular phones to send their messages. In English it is known as a "short code".
Masked sender. This is what the sender is called when the short or long b2b email list number is "masked" and replaced by a string of up to 11 characters. For example, when the message says AURONIX instead of 43900.
Grey routes. A grey route in telecommunications is one that does not pay the operator. They have the advantage of being cheaper, but the disadvantage is that they are typically illegal routes that use security or pricing "loopholes" in the operator and can be closed at any time, or the messages simply do not reach the recipients, without giving any notice to the person who is buying them.
Masking. Masked sending is when of a numeric sender, for example when SMS arrive as TELCEL, UNONOTICIAS or BANORTE. To use this service, it is necessary to use a short code and have the permission of the brand and the operator.
RCS - Rich Communication Services. Rich Communication Services is an initiative to provide communication services between operators, based on IP multimedia subsystem. This technology is expected to succeed SMS. It can be used in A2P and P2P modes.