It should accurately identify the relevant period and actual responsibilities. A present role does not automatically establish the historical qualifying year.
Keep the chronology honest
Explain promotions or changed duties rather than rewriting earlier work. A desired filing date cannot supply missing facts.
The backward clock is the qualifying year, which must be continuous and must fall within the three years before the petition, so an employee who has already been working in the United States for an extended period may find the window closing. L-1A requires qualifying organizations that are doing business, a managerial or executive U.S. position, and twelve continuous months of qualifying employment abroad during the relevant preceding thirty-six months. Only then does the petition go in, and processing time should be checked against current USCIS posted times rather than assumed; premium handling, where available, shortens adjudication but not preparation. If the four-month secondment falls in the middle of the only candidate period, options include waiting until a fresh twelve months accumulate in Canada or documenting that the secondment was intermittent business travel rather than a US placement.