have
The two authors have the same initials.

be known by, become known by
She's always been known by her initials.

use
bear, carry (esp. BrE)
A stone bears the initials ‘R.P.’, which stand for ‘Ralph Piggot’.

carve, embroider, engrave (sth with), mark sth with, put, sign, write
He carved his initials in the rock.
Now that she was chief executive officer, she could put the initials CEO after her name.

stand for sth

initial for
SC are the initials for Santa Catarina.

Initial is used with these nouns:
aim, appearance, appointment, approval, assault, assessment, burst, cause, conception, confusion, consultation, cost, deployment, diagnosis, disappointment, discussion, draft, encounter, enquiry, enthusiasm, estimate, euphoria, evaluation, examination, excitement, expectation, failure, finding, flurry, funding, guess, hesitation, hiccup, impact, impetus, impression, impulse, indication, instalment, instinct, investment, letter, manifestation, meeting, momentum, move, nervousness, observation, offer, onslaught, optimism, outlay, payment, period, phase, planning, preparation, projection, promise, proposal, reaction, recommendation, reconnaissance, reduction, refusal, reluctance, rent, report, request, reservation, resistance, response, result, rise, scepticism, selection, setback, shock, shyness, sketch, spurt, stage, step, stimulus, study, success, surge, surprise, suspicion, target, test, thought, training, velocity, version, visit, warning