Aromatic polyimide polymers and copolymers are described that have pendant side-chain crosslinkable groups. In the context of a method, a method is provided that includes identifying a request to perform at least one function of a user device and identifying at least one watermark template. This visual display embodies the ISL’s syntax and structures how the user employs it to build sentences. Based on the measured light, it is determined whether a dye color is present in the water sample.