если "значительное" в смысле "значимое", т.е. "отличное от других"

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Typically I would say there isn't enough context, but in this case I'm not sure more context would be helpful. It seems to me the author of this sentence used the term vaguely, and may have meant a number of things.

If he/she was trying to sugggest that the title of the article is large/impressive in size, bearing, dignity or grandeur then "znachitelnnyj" should perhaps be rendered as "imposing."

On the other hand, if it carries a great deal of information about the contents of the article (though it doesn't seem to), then it may be translated as "meaningful."

If it contains much information and communicaes it succinctly, it may be "expressive."

If it stands out from other titles, or just stands out in its context it may also be "conspicuous/prominent/notable or salient."

a "distinctive title" seemd to have a more technical meaning (judging by google hits);
I don't think a "suggestive title" must necessarily have sexual connotations, though it seems to be used that way quite a bit; it may also mean "evocative," and perhaps better reserved for literary/poetic titles.

If I had had to write a short answer I would have cast my vote with "meaningful" but not with significant. Something doesn't sound right about it.

Best.

Having enjoyed Sergey L's exhaustive analysis of the situation, I would suggest this word which appears to cover all the branches he analyzes

что дает нам значение "внушительный", "солидный", и 35 тыс закавыченных хитов

или

catchy title - захватывающий, привлекающий внимание.

As a result the RSA disappeared, and instead of it a "new" political structure with a much-promising title Alternative - Labour Party (Alternatywa - Partia ...
en.wikipedia.org/wiki/Daniel_Podrzycki