The phrase "a minor extra" is correct and usable in written English.
It can be used to refer to something that is an additional, but not significant, component or detail in a given context.
Example: "The report included a minor extra that provided additional insights into the data analysis."
Alternatives: "a small addition" or "a slight extra".
Being formal in a snail-mail letter is only a minor extra inconvenience on top of finding pen, paper and envelope, writing it, and then folding, stuffing, addressing, stamping and posting the missive.
One case of a minor extra rule being added for a particular match is "no drawing or resigning during the first 30 moves" in the London Chess Classic on 8 15 December 2009 at Olympia, London.
When using a slightly softer assumption of testing all MAF thresholds, we found that incorporating functional information from protein coding function algorithms generally improved the efficiency of the test, and added only a minor extra computational burden.
(A minor extra constraint precludes the repeated connection of any pair of cells).
In some ways, the "relative" or "shape-based" model described here is a minor extra step added to the basic model and we are deliberately treating it as such in this paper.
Furthermore, the proteins were only active in conditions above pH 7 and raising the pH up to 9.5 caused a minor extra activation of the reactions (Supplementary Figure S1C).
"You may get some minor extra credit at work for that quick response, but it's not a thoughtful reply," she explains.
In fact, the slight overheads are caused by two main factors: the API libraries (AWS Java SDK version 1.8.3 and jclouds Rackspace API libraries version 1.7.0) used (by OCSO) decide the main processing time; USAMS components also consume minor extra time while processing the obtained data, preparing for the operations and other additional tasks.
Adult patients (aged ≥ 18 years) with isolated TBI or associated with minor extra-cranial injuries (defined as all non-head Abbreviated Injury Scale < 3) were included.
Sometimes these have been minor extras and more recently, from the iPhone 7 Plus onwards, this has manifested as one camera on the smaller phone, two on the larger.
But it is not as much force as a rook for a minor piece, or an extra pawn.
