Having friends who occupy just about every position in terms of churchmanship I know that some will never be seen wearing a dog collar whilst others appear naked without a cassock (all thirty-nine buttons done up) and a beretta (of the hat, not firearm, variety). Indeed, what we wear is often an indicator of the way in which we 'do' our theology but perhaps we don't wear it for ourselves but others.
One of the most important things about the dog collar is that it identifies us as being clerics. It's not just part of the uniform, it's a statement of intent; it's a proclamation of commitment and availability.
The wearing of a dog collar is not some fiendishly 'popish' statement, nor is it a fashion statement (although some try to make it such and far too often fail) or an imposition. The collar is something that is somewhat kergymatic (by which I mean 'proclamatory') and so brings an added dimension to the person wearing it - one that is bounded by ontology ('being'), proximity (the 'parakletos' that is 'coming alongside') and the servanthood that is 'diakonos'. It speaks of God's Kingdom made real and present in the here and now.
What I'm suggesting is that the wearing of a dog collar finds its parallels in a taxi cab with its 'For Hire' light blazing availability in a dim and hurried world of 'too busyness' combined with 'not bothered ness'. The collar screams, in a John Inmanesque manner, 'I'M FREE'!
It is kergymatic in that it is the herald of the Good News that is the Gospel of Christ made present in the reality in which we are found; proclaimed and made real in the fact that 'the Kingdom of God is made real and come into your presence!' Indeed the collar speaks of the basileia - the Kingdom proclaimed by Jesus in so many places in the New Testament in the way that He did.
Being a priest is more than merely playing a part, it is not what we do but who we are - it is therefore an ontology reality - and this is proclaimed, or perhaps 'supported', by our 'ring of confidence'. Not an item of dress but a statement of fact.
Jesus speaks of the Holy Spirit as 'one who comes alongside' - using the word 'Paraclete' - and this is our role as, enabled and filled with that same Holy Spirit, we engage in our calling. Again, it is the collar that speaks of this as we serve them in our diaconal role.
To choose when we will, and will not, wear our collars is therefore to choose when we will, or will not, be the priests we are called to be. If wearing it says 'available' then what does not wearing it communicate? (postscript: for many, the only way they can identify pastors or priests as such is by the clothing and so to wear when we choose - this means on/off/on/etc and do nor refer to making the choice through theological position - is to choose when to be identified and therefore also available).
A Vicar I knew used to occasionally frequent a pub during the lunch- hour session and did so without his collar. Slowly he became known to the regulars and was incorporated into their conversations and friendship. Then one day one of the regulars knocked at the vicarage door, only to find it to be opened by the same man he drank with, wearing a dog collar and he wasn't best pleased. The reason for thus was that he'd said things and related events to someone he considered to be a friend, not a Vicar!
The relationship with those in the pub' was broken and it damaged the work of the church in that place too. Integrity and calling demand that we are WYSIWYG (What You See Is What You Get) - and the collar sets the tone, expectation and reality.
The question is - do we?