This paper studies a Coded Event-triggered Control (CEC) for a class of nonlinear systems under any initial condition. To reduce communication burden, the CEC is designed from the encoding-decoding viewpoint by which only $m$-length string is transmitted for each communication between CEC and actuator. If a more general Entry Capture Problem is encountered, such control design will be rather complicated yet challenging where the performance constraints are satisfied some time after (rather than from the beginning of) system operation, rendering normally employed prescribed performance control invalid because they may be not defined in the initial interval. By introducing auxiliary functions, we develop a Self-adjustable Prescribed Performance (SPP) mechanism which can flexibly adjust the symmetric or asymmetric performance boundaries to accommodate different initial conditions, providing an effective solution for the underlying tracking problem. In this way, the resulted CEC can not only consume less communication resources but also regulate the tracking error under any initial condition into an allowable set before a given time in a bounded and customizable manner. Simulation results verify and clarify the theoretical findings.