I’m confused. In your last sentence, do you mean “weekly indemnity” or “WAGE indemnity”? In either case, terms of a contract are always open to interpretation when they’re not clearly defined in the agreement. The Q becomes: What did the parties intend? To make that determination, courts and arbitrators will look at not only the contract language itself, but extrinsic materials including how you interpreted the language in actual practice. The fact that you have employees fill out short term weekly indemnity forms is evidence supporting your interpretation of the language’s pertaining only to short-term leaves. But it’s not a slam dunk, especially if you ever did apply the language to top off benefits of employees on longer term leaves.
Of course, the union may have other evidence supporting its interpretation (if the union is, in fact, arguing that the language pertains to longer leaves). If you’re currently not in a dispute with the union, you might consider proposing amending the collective agreement to add new language clarifying the meaning of the term. On the other hand, if the union hasn’t brought up the issue, bringing it to its attention could wake a sleeping volcano.
Hope that helps and sorry for the long wait. Glenn