A method comprising: receiving, at a user interface located on a host aircraft, a first user selection of one or more display parameters; receiving target aircraft information from a communications system on the host aircraft; generating a graphical user interface display for presentation on a display coupled to a processing device on the host aircraft, the graphical user interface display comprising: a main section configured to present the one or more display parameters and one of a plan view or In-Trail Procedure vertical profile view showing flight levels, ITP distance information, and target icons associated with target aircraft; an ITP procedural guidance section configured to present steps for executing an ITP request for a flight level change according to ITP; a target status section configured to provide information about target aircraft that are associated with one or more of the target icons that are selected in the main section; and an ITP advisory message section configured to provide information relating to selections of either one or more of the flight levels or one or more of the target aircraft that are made within the main section when the one or more flight levels are invalid or when the one or more of the target aircraft are invalid or unavailable ITP reference aircraft; receiving a second user selection of a desired flight level; uniquely identifying a current flight level of the host aircraft; responsive to determining all target aircraft within a predefined lateral envelope relative to the host aircraft, between the current flight level of the host aircraft and the desired flight level, that satisfy ITP initiation criteria according to ground speed differential, ITP distance, and relative altitude, uniquely identifying, in a first way, the target icons associated with said target aircraft; and responsive to determining that one of the target aircraft within the predefined lateral envelope relative to the host aircraft, between the current flight level of the host aircraft and the desired flight level, does not satisfy the ITP initiation criteria, uniquely identifying, in a second way that is different than the first way, the target icon associated with said aircraft that are located between the current flight level of the host aircraft and the desired flight level from the other target icons. receiving, at a user interface located on a host aircraft, a first user selection of one or more display parameters; receiving target aircraft information from a communications system on the host aircraft; generating a graphical user interface display for presentation on a display coupled to a processing device on the host aircraft, the graphical user interface display comprising: a main section configured to present the one or more display parameters and one of a plan view or In-Trail Procedure vertical profile view showing flight levels, ITP distance information, and target icons associated with target aircraft; an ITP procedural guidance section configured to present steps for executing an ITP request for a flight level change according to ITP; a target status section configured to provide information about target aircraft that are associated with one or more of the target icons that are selected in the main section; and an ITP advisory message section configured to provide information relating to selections of either one or more of the flight levels or one or more of the target aircraft that are made within the main section when the one or more flight levels are invalid or when the one or more of the target aircraft are invalid or unavailable ITP reference aircraft; a main section configured to present the one or more display parameters and one of a plan view or In-Trail Procedure vertical profile view showing flight levels, ITP distance information, and target icons associated with target aircraft; an ITP procedural guidance section configured to present steps for executing an ITP request for a flight level change according to ITP; a target status section configured to provide information about target aircraft that are associated with one or more of the target icons that are selected in the main section; and an ITP advisory message section configured to provide information relating to selections of either one or more of the flight levels or one or more of the target aircraft that are made within the main section when the one or more flight levels are invalid or when the one or more of the target aircraft are invalid or unavailable ITP reference aircraft; receiving a second user selection of a desired flight level; uniquely identifying a current flight level of the host aircraft; responsive to determining all target aircraft within a predefined lateral envelope relative to the host aircraft, between the current flight level of the host aircraft and the desired flight level, that satisfy ITP initiation criteria according to ground speed differential, ITP distance, and relative altitude, uniquely identifying, in a first way, the target icons associated with said target aircraft; and responsive to determining that one of the target aircraft within the predefined lateral envelope relative to the host aircraft, between the current flight level of the host aircraft and the desired flight level, does not satisfy the ITP initiation criteria, uniquely identifying, in a second way that is different than the first way, the target icon associated with said aircraft that are located between the current flight level of the host aircraft and the desired flight level from the other target icons.