It is time that more thought was given to "portable seniority", based mainly on flying hours,hours rather than it being confined to years within the current employer only. This system traps people into one company, often to their long term disadavantage. It certainly puts many into a career straitjacket. The unions have supported single company seniority lists,- probably to protect those in the legacy companies as they form the big battalions of membership,- but it is very unlikely that this is to the benefit of the pilot community as a whole. Big opportunity for some new thinking.