Self-assembly of particle-like dissipative solitons, in presence of mutual interactions, emphasizes the vibrant concept of soliton molecules in varieties of laser resonators. Controllable manipulation on the molecular patterns, held by the degrees of freedom of internal motions, still remains challenging to explore more efficient and subtle tailoring approaches for the increasing demands. Here, we report a new phase-tailored quaternary encoding format based on controllable internal assembly of dissipative soliton molecules. Artificial manipulations on the energy flow of soliton-molecular elements stimulate the deterministic harnessing on the assemblies of internal dynamics. Self-assembled soliton molecules are tailored into four phase-defined regimes, thus constituting the phase-tailored quaternary encoding format. Such phase-tailored soliton assemblies are endowed with great robustness, mostly resistant to the fiber nonlinearity and complicated timing jitter. All these results experimentally demonstrate the programmable phase tailoring based on the gain-governed energy flow and exemplify the application of the phase-tailored quaternary encoding format, prospectively promoting the large-capacity all-optical storage in soliton communications.