TARDIS A TARDIS — sometimes styled Tardis , but also called a TT Capsule — was the primary space - time vehicle used by the Time Lord s of Gallifrey . Name . " TARDIS " was an acronym that Susan purportedly devised . Susan defined the acronym with both the singular " dimension " ( TV : " An Unearthly Child " ) and the plural " dimensions " . ( AUDIO : " The Beginning " ) Susan claimed to have come up with the acronym while in her first trip inside such a ship , ( AUDIO : " The Beginning " ) although another account stated that she only thought of it while on 1963 Earth . ( PROSE : " Time and Relative " ) The First Doctor expressed familiarity with the term when Susan first said the word " TARDIS " aloud , which Susan didn ' t believe . ( AUDIO : " The Beginning " ) Although some Time Lords , like Castellan Spandrell ( TV : " The Deadly Assassin " ) and Romana I , ( TV : " The Pirate Planet " ) utilised the more generic name " TT capsule " , others were perfectly familiar with Susan ' s supposed acronym . ( TV : " The Three Doctors " , " The Name of the Doctor " , PROSE : " Lungbarrow " , AUDIO : " Human Resources " ) According to one account , TT capsule was an early name for TARDISes , with Gallifreyans of the Racnoss War not being familiar with the latter term . ( AUDIO : " Empire of the Racnoss " ) As Bill Potts pointed out to the Twelfth Doctor , though , the acronym would likely only work in English . ( TV : " The Pilot " ) Some beings on the fringes of Time Lord society , like the Sisterhood of Karn , also knew the acronym without being prompted by the Doctor or his companion s . ( TV : " The Brain of Morbius " ) There was a slight discrepancy as to the precise meaning of the acronym . Though Susan described it as " dimensions " when recalling her initial trip in the TARDIS , ( AUDIO : " The Beginning " ) while on 20th century Earth , she referred to it as the singular " dimension " . ( TV : " An Unearthly Child " ) Vicki pluralised the " dimension " when she explained the term to Steven , making it " Dimension " s " " . ( TV : " The Watcher " ) This interpretation seemed to hold for a time , being used by several subsequent companions and Doctors . ( TV : " The Daleks ' Master Plan " , " The Massacre of St Bartholomew ' s Eve " , " The War Machines " , " The Wheel in Space " , " The War Games " , " The Creature from the Pit " , " Four to Doomsday " , " Delta and the Bannermen " ) Nevertheless , the singular " Dimension " , may have been " more correct " , as the Doctor ' s fifth , ( TV : " Frontios " ) eighth , ( TV : " Doctor Who " ) ninth , ( TV : " Rose " ) tenth ( TV : " Smith and Jones " ) and twelfth incarnations ( TV : " The Pilot " ) consistently preferred the singular form , as did the Doctor ' s TARDIS itself when its matrix was transplanted into Idris ( TV : " The Doctor ' s Wife " ) and Rose Tyler . ( TV : " Turn Left " ) The " dedication plaque " in the Doctor ' s TARDIS also referred to the ship as " Time and Relative Dimension in Space " , favouring the singular form . ( TV : " Amy ' s Choice " ) The Twelfth Doctor once claimed to Osgood that " he " made up the term TARDIS from the initials , " Totally and Radically Driving in Space " . Osgood also mentioned that she had heard " a couple of different versions " of what TARDIS stood for . ( TV : " The Zygon Inversion " ) Flight . TARDISes usually moved through time and space by " disappearing there and reappearing here , " ( TV : " Rose " ) a process known as " materialisation " . This was controlled by a component called the dematerialisation circuit . ( TV : " Terror of the Autons " ) If a TARDIS ' relativity differentiator was missing or malfunctioning , then a TARDIS could only reappear in a different location in time , and not space . ( COMIC : " The Stolen TARDIS " ) TARDISes also could fly through space like conventional spacecraft , but doing so for prolonged periods could damage the ship , at least in the case of the Doctor ' s TARDIS . ( TV : " The Runaway Bride " ) A TARDIS was meant to have six pilots ; ( TV : " Journey ' s End " ) however , the Doctor piloted the TARDIS on his own which led to it often jumping about in the Time Vortex and being an unpleasant ride for the passengers . During operation , a distinctive grinding and whirring sound , nicknamed the vwoorpy by Alice Obiefune , ( COMIC : " The Then and the Now " ) was usually heard . ( TV : " An Unearthly Child " et al ) River Song once demonstrated that the Doctor ' s TARDIS was capable of materialising silently , teasing the Doctor that the noise was actually caused by him leaving the brakes on . ( TV : " The Time of Angels " ) However , other newer TARDISes , flown by other pilots such as the Master , ( TV : " Colony in Space " , " The King ' s Demons " ) the Rani ( TV : " Time and the Rani " ) and the Monk , ( TV : " The Daleks ' Master Plan " ) made the same sound in the course of their normal operation , as did the Doctor ' s when piloted by other Time Lords . ( TV : " The Claws of Axos " , " The Pirate Planet " ) The Minyan s ' computer recognised the sound as associated with Time Lord ships . ( TV : " Underworld " ) The Doctor himself also materialised his TARDIS more than once without making the distinctive noise . ( TV : " The Dalek Invasion of Earth " , " The Impossible Astronaut " , " The Time of the Doctor " ) This sound was also made by other devices : SIDRAT s , a craft similar to TARDISes used by the War Lord s ; ( TV : " The War Games " ) a Time Lord who appeared to the Third Doctor ( without using any visible means of transport ) to warn him of the appearance of the Master ; ( TV : " Terror of the Autons " ) when the Time Lords provided the Third Doctor with a new dematerialisation circuit , it appeared on a table making this sound ; ( TV : " The Three Doctors " ) and when the Doctor modified Skagra ' s invisible spaceship to travel like a TARDIS , again , this sound was heard . ( TV : " Shada " , AUDIO : " Shada " ) When a TARDIS materialised , it would sometimes result in a strong wind and small tremors , enough to shake wine glasses , in the area where it appeared . ( TV : " Love & Monsters " , " Smith and Jones " , " The Eleventh Hour " , " The Lodger " , " The Big Bang " , TV : " End of Days " ) The Fifth Doctor once explained that this was caused by " Ionisation . Particles in the air being shunted around ; making space . " ( AUDIO : " The Boy That Time Forgot " ) If a TARDIS materialised in a space occupied by another object , that object might appear inside the TARDIS . ( TV : " Bad Wolf " , " The Snowmen " ) Once , the Eleventh Doctor landed an incomplete TARDIS in his own TARDIS and on top of an Ood ; the Ood was atomised . ( TV : " The Doctor ' s Wife " ) Conversely , a TARDIS could dematerialise while leaving its occupants behind . ( TV : " Blink " ) If a TARDIS landed in the same space and time as another TARDIS ( TV : " The Time Monster " ) , or even if they simply collided while in the vortex a time ram could occur , destroying both TARDISes , their occupants and even cause a black hole that would tear a hole in the universe — one the exact size of Belgium . ( TV : " Time Crash " ) . However , time rams could be avoided by materialising inside the other TARDIS . This act itself also had inherent dangers , including space loop s . ( TV : " Logopolis " , " Space " / " Time " ) . TARDISes had trouble materialising during time loop s . ( TV : " The Lodger " , TV : " The Wedding of Sarah Jane Smith " , TV : " The Pirate Planet " ) , and severe time distortions would make it impossible for a TARDIS to land without a signal to lock onto . ( TV : " The Angels Take Manhattan " ) Types . TARDISes were generally referred to using the nomenclature " Type X " ( TV : " The Pirate Planet " et al . ) or " X - form " . ( PROSE : " The Book of the War " et al . ) The earliest known model of TARDIS was the Type 1 , which was poorly designed , dangerous to operate , and difficult to start . Some of them had minds of their own , with a history of escaping and roaming the Universe . ( PROSE : " Heart of TARDIS " ) Professor Chronotis had a Type 12 TARDIS . ( PROSE : " Shada " ) The First Doctor had a Type 50 TARDIS ( AUDIO : " Prisoners of Fate " ) before he escaped Gallifrey in an out - dated ( TV : " The Doctor ' s Wife " ) Type 40 ( PROSE : " The Deadly Assassin " , " The Ribos Operation " , et al . ) Mark 3 . ( TV : " Let ' s Kill Hitler " ) The Monk ' s TARDIS was a " Mark 4 " , and the First Doctor noted that there had been " quite a few changes " made compared to his own model . ( TV : " Checkmate " ) By the time of the Doctor ' s fourth life , the entire Type 40 line had been retired from use . ( TV : " The Deadly Assassin " ) The Master had a Type 45 . ( PROSE : " The Dark Path " ) Anzor ' s TARDIS was a Type 50 . ( AUDIO : " Mission to Magnus " ) The fifth incarnation of the Doctor once remarked that he should have upgraded to a Type 57 TARDIS . ( TV : " Warriors of the Deep " ) On another occasion , he noted that a Type 70 would allow him to break through a temporal distortion grid , but that his Type 40 was not cut out for such a " brute force approach " . ( AUDIO : " Singularity " ) Romana II , ( AUDIO : " A Blind Eye " ) the Clocksmith , ( AUDIO : " The Doomsday Chronometer " ) and Vansell used Type 70 s . ( AUDIO : " The Sirens of Time " ) The Type 90 was the first generation engineered for war . Their pilots were regenerated to meld into the machinery ; they primarily blocked off time travel routes that could be used for enemy escape during combat . ( PROSE : " The Book of the War " ) Christine Summerfield described them as big brass spheres . ( PROSE : " Dead Romance " ) War TARDIS es could map their interior dimensions onto the outer dimensions , appearing deliberately indiscreet . ( PROSE : " The Ancestor Cell " , " The Book of the War " ) Both Type 91 s ( PROSE : " The Brakespeare Voyage " ) and Type 94 s were War TARDISes . ( PROSE : " The Quantum Archangel " ) On more than one occasion , the Doctor encountered heavily armed battle TARDIS es carrying time torpedo es , developed during their fifth incarnation or earlier . ( COMIC : " The Stockbridge Horror " , AUDIO : " Neverland " ) After the Eighth Doctor attached Compassion V ' s Remote receiver to his TARDIS , ( PROSE : " The Blue Angel " ) the block transfer calculation s changed her biodata and she became the first and only Type 102 TARDIS . ( PROSE : " The Shadows of Avalon " , " The Book of the War " ) Before this , another TARDIS was stated to be a Type 102 , used by Epsilon Delta . ( PROSE : " The Dimension Riders " ) Later , model numbers would become standardised so that ‘ Type 102 ’ referred only to Compassion . ( PROSE : " The Book of the War " ) The Time Lords knew that , during the War in their future , they would be using humanoid TARDISes . ( PROSE : " The Shadows of Avalon " , " Alien Bodies " ) Lady President Romana III sent Celestial Intervention Agency operatives in Type 98 TARDISes to capture Compassion , but she escaped . ( PROSE : " The Shadows of Avalon " ) The Second Doctor was briefly assigned a Type 97 while working for Celestial Intervention Agency . ( PROSE : " World Game " ) While Compassion still evaded them , the Great House s began the 101 - form Project to engineer humanoid timeships without Compassion ' s help . They tried to upgrade an old TARDIS , but she went mad and escaped ; ( PROSE : " Toy Story " , " The Book of the War " , " Of the City of the Saved . . . " ) they also tried to pull one of Compassion ' s future children , Antipathy , backwards through time into their control . However , neither project succeeded . ( PROSE : " Of the City of the Saved . . . " ) Eventually , Compassion made a deal with the War King and agreed to mother the humanoid " 103 - form " ( PROSE : " The Book of the War " ) or " Type 103 " TARDISes . The Eighth Doctor met a Type 103 named Marie during the auction for the Relic . ( PROSE : " Alien Bodies " ) Features and functions . Dimensionally transcendental . One of the key features of a TARDIS was that the interior existed in a dimension different from the exterior . The main application of this concept was that they were bigger on the inside than the outside . ( TV : " An Unearthly Child " et al ) This feature required use of " dimensional dams " , which , upon the death of a TARDIS , would leak through . One such effect of this was the TARDIS exterior growing to a gargantuan size . ( TV : " The Name of the Doctor " ) The Fourth Doctor once tried to explain the phenomenon to Leela by using two boxes , one smaller than the other . He placed the larger one further away , so it appeared as if it could fit within the small box . He then explained that if the big box could be accessed where it was from the small box , the small box would be " bigger on the inside " . However , Leela dismissed this as " silly " . ( TV : " The Robots of Death " ) Nardole later used a similar analogy to Bill Potts , stating she ’ d have to imagine “ a very big box fitting inside a very small box ” , before adding “ [ she ’ d ] have to make one ” , and that it ’ s the second part people have trouble with . ( TV : " The Pilot " ) Chameleon circuit . One feature of TARDISes was their ability to blend into their surroundings once they landed . If working properly , a chameleon circuit could assess the surroundings of a time and place just before arrival and change the exterior to resemble something common to that landscape . ( TV : " An Unearthly Child " , " Rose " , " Boom Town " ) On the one occasion that the Doctor temporarily got the chameleon circuit on his own TARDIS working again after leaving London in 1963 , it selected forms very incongruous to its surroundings . ( TV : " Attack of the Cybermen " ) However , were the mechanism functioning correctly , it would have also been programmable from a keyboard on the TARDIS ' main console . The Doctor once demonstrated to Adric how he would change the TARDIS into a pyramid , if the chameleon circuit were functioning properly . ( TV : " Logopolis " ) The Master was able to produce an architectural column in sometimes incongruous environments like the Pharos Project or Heathrow Airport ( TV : " Logopolis " , " Castrovalva " , " Time - Flight " ) , and the Monk stated that he chose to make his TARDIS look like a Saxon sarcophagus . ( TV : " Checkmate " ) The Doctor once entered the Monk ' s TARDIS and changed its appearance from a pillar of stone to a police box identical to his own TARDIS . ( TV : " The Daleks ' Master Plan " ) When on Gallifrey , and presumably not utilising the chameleon circuit , some TARDISes were seen to resemble a plain rectangular cabinet with an outwards - sliding door on the front — a form also used by SIDRAT s . ( TV : " The War Games " ) When the Doctor stole his Type 40 TARDIS from the repair shop , it and others nearby resembled stone cylindrical structures with sideways - sliding doors . ( TV : " The Name of the Doctor " ) The TARDIS that the Twelfth Doctor and Clara Oswald stole from the same workshop had the same exterior design as the others . This TARDIS also had a broken chameleon circuit , as stated by Ashildr leaving it stuck in the form of an American diner after landing on Earth in Nevada . ( TV : " Hell Bent " ) Living machines . Organic machines . TARDISes were incredibly complex machines . The nature of their construction was such that they were said to be grown rather than constructed . ( TV : " The Impossible Planet " ) This could be done either from a seed ( PROSE : " The Nameless City " ) or a cutting ( AUDIO : " Black and White " ) . Because computer s were unable to withstand the reality - changing stress , TARDISes required morphologically unstable living organic matter , or protoplasm , for their Block Transfer Computation s . The outer plasmic hull , interior configuration , and a host of other details were derived from this function , as well as possibly a TARDIS ' link with the Eye of Harmony . ( PROSE : " " ) According to the Second Doctor , his TARDIS was a microbiologically sterile environment . ( TV : " The Moonbase " ) Sentient machines . Due to the level of complexity in their construction , TARDISes had a degree of sentience , and they could even take independent action , as when the Doctor ' s TARDIS resurrected Grace Holloway and Chang Lee . ( TV : " Doctor Who " ) Some advanced TARDISes , such as Compassion , were fully sentient beings in their own right . ( PROSE : " The Shadows of Avalon " ) Two near TARDISes could engage in a psychic conversation , audible by the bystanders . ( COMIC : " The World Shapers " ) TARDISes often " mourned " the death of their Time Lord pilots , even committing suicide by flying into a sun or hurling themselves into the Time Vortex . The Fifth Doctor claimed there was " an elephants ' graveyard " of TARDISes somewhere at the end of time . ( AUDIO : " Omega " , " The Axis of Insanity " ) Since they were considered alive , a graveyard for TARDISes was provided in an under croft beneath the Capitol on Gallifrey . ( PROSE : " Engines of War " ) In a parallel world , the death of the Tenth Doctor caused the TARDIS to slowly die . ( TV : " Turn Left " ) In another alternative timeline , the Eleventh Doctor ' s death had the same effect on the TARDIS , though on this occasion the ship ' s dimension dams started breaking down , causing the exterior to grow . The console was also replaced by an " open wound " into the Doctor ' s time stream . ( TV : " The Name of the Doctor " ) Even if in their first travels the First Doctor showed to be not fully aware of the conscience of his machine , ( TV : " The Brink of Disaster " ) since the Doctor ' s TARDIS displayed these organic traits , he considered it to be alive . He talked to and stroked parts of the TARDIS when he operated it . ( TV : " School Reunion " ) He spoke of mechanical difficulties as medical or biological conditions like " indigestion " ( TV : " Doctor Who " , " The Impossible Planet " ) and " digesting " . ( TV : " The Runaway Bride " ) He once commented that a TARDIS was " more like a person " . ( TV : " The Five Doctors " ) On one occasion , the Doctor ' s TARDIS manifested an avatar to help him fight a mental battle , taking on the forms and personas of the various companion s who had ridden in it – however , this was when the Doctor was unconscious and battling within his own mind . ( COMIC : " The Forgotten " ) When Amy told him she thought him mad for talking to a time machine , the Eleventh Doctor told her the TARDIS could , in fact , hear him . ( PROSE : " Night of the Humans " ) When Chang Lee seemed to activate the Doctor ' s console upon leaning on a pillar and had the wooden doors to the Cloister Room open in front of him automatically , explained that the TARDIS liked him . ( TV : " Doctor Who " ) When the matrix of the Doctor ' s TARDIS was placed inside the body of Idris , it was shown that they were , in fact , sentient beings who did possess some degree of free will . The TARDIS said , in its human body , " All of my sisters are dead . " She also told him that the navigation problems that had plagued him throughout his travels were due to her taking him where he " needed to go " rather than just where he wanted to go . ( TV : " The Doctor ' s Wife " ) The Eleventh Doctor told Alice Obiefune that a bond existed between a TARDIS and the individual who piloted it . If the bond was broken and the TARDIS could no longer " trust " the individual flying it , a TARDIS was programmed to return to Gallifrey . If unable to return to Gallifrey , a TARDIS was then programmed to find the next nearest Time Lord . After the Doctor ' s TARDIS locked him out and left him in 2015 London , the Doctor believed his bond with the TARDIS was broken . He later found the TARDIS and was shocked when his mother stepped out in full Gallifreyan robes . ( COMIC : " The Comfort of the Good " ) Security features . Before a TARDIS was fully functional , it needed to be primed with the symbiotic nuclei of a Time Lord ' s cells to create a molecular stabilisation system to protect a TARDIS ' occupants against destabilisation . Once it was properly primed , it could be used safely by any species . ( TV : " The Two Doctors " ) If a TARDIS were to be used by anyone other than its owner and his familiars , it would assault their minds , which may lead to memory loss . ( PROSE : " Echoes of Future Past " ) When the TARDIS needed more power to take off , rooms could be jettisoned to provide this power . This feature was used to escape both a gravity bubble and Event One ( TV : " Logopolis " , " Castrovalva " ) , and to provide the extra power required to both leave the universe and re - enter it . ( TV : " The Doctor ' s Wife " ) When the TARDIS was under attack from physical objects , the pilot could activate siege mode . This turned the exterior into a cube etched with Gallifreyan writing and sealed the entrance . ( TV : " Flatline " ) " Every TARDIS " was equipped with a spare " empty dimension " , a conduit to which could be opened to imprison someone in with a button in the control room , as the Fourth Doctor did to the Malevilus Magog . ( COMIC : " Doctor Who and the Iron Legion " ) Computer interfaces . TARDIS computer interfaces included : Specific TARDISes . The Doctor ' s TARDIS . The First Doctor stole his TARDIS . ( TV : " The War Games " ) At the time he had " borrowed " it , it was on Gallifrey for repairs . ( TV : " Logopolis " , " The Name of the Doctor " ) However , the TARDIS itself , temporarily in the human body of Idris , said that it had " planned " for him to steal it ; it had left its doors unlocked so that he could walk in . It considered itself to have " stolen " the Doctor as much as the Doctor thought they had stolen their TARDIS . ( TV : " The Doctor ' s Wife " ) By the time of their fourth incarnation , all Type 40s had been decommissioned , save his . ( TV : " The Deadly Assassin " ) Following the events of the Last Great Time War , the Tenth Doctor believed his was the last TARDIS in existence . ( TV : " Rise of the Cybermen " , " The Doctor ' s Wife " ) According to the Moment , the sound of the TARDIS materialising was enough to bring hope to anyone who heard it , no matter how lost they were . ( TV : " The Day of the Doctor " ) Possessed by other renegades . The Master had at least two TARDISes . According to the Doctor , the Master ' s had a Mark II dematerialisation circuit . ( TV : " Terror of the Autons " ) The Rani , ( TV : " The Mark of the Rani " ) the Monk ( TV : " The Time Meddler " ) and Iris Wildthyme ( PROSE : " The Scarlet Empress " ) also had TARDISes . While not technically a " renegade , " Salyavin ( a . k . a . Professor Chronotis ) possessed a Type 12 TARDIS , with its controls appearing as simple panels hidden in an old book cupboard - type cabinet , and its control room " desktop " set as a university professor ' s library and study ; his main TARDIS ' disguise was that of his quarters at Cambridge University ( PROSE : " Shada " ) Ashildr and Clara Oswald ' s TARDIS . Stolen by the Twelfth Doctor from the Workshops on Gallifrey , the Doctor and Clara Oswald described the interior of this TARDIS as " basic " and " all white " . The control room resembled that of the Doctor ' s TARDIS during his early travels with it . It had a console , scanner screen , panels with Time Lord writing and inner doors . The Doctor used this TARDIS to visit the final moments of the universe , encountering Ashildr there . This TARDIS was , after the Twelfth Doctor erased his memory of Clara Oswald , piloted by Clara and Ashildr . They used it to return to Earth to retrieve the Doctor ' s TARDIS and then moved it to Nevada . They were unable to get the chameleon circuit working , leaving it stuck in the form of an American Diner . After dropping the Doctor off , Clara declared that she would return to Gallifrey " the long way around " , using the TARDIS to have some more adventures of their own . ( TV : " Hell Bent " ) Unique TARDISes . Compassion ( a former member of the Remote ) evolved into a TARDIS , the prototype of the sentient Type 102 , the only one of that type . The first generation of mass produced sentient TARDISes was the Type 103 . ( PROSE : " The Shadows of Avalon " ) Idris and the Eleventh Doctor also built a junk TARDIS out of dead TARDIS parts from the Bubble universe ' s junkyard . ( TV : " The Doctor ' s Wife " ) Other types of TARDISes . A Type 98 TARDIS had a holographic scanner . ( PROSE : " The Shadows of Avalon " ) Copies of TARDIS technology . During the Doctor ' s second incarnation , the renegade Time Lord known as the War Chief provided similar time ships called SIDRAT s to the War Lord s to further their plans of conquest . When they learned of this , the Time Lords placed a force field around the War Lord homeworld . ( TV : " The War Games " ) The Fourth Doctor instructed Skagra ' s ship on how to alter her own circuitry so she could de - and re - materialise like a TARDIS . ( TV : " Shada " ) When the Skith probed the Doctor ' s mind , they gained knowledge of the TARDIS and made their own version , the SKARDIS . ( COMIC : " The Age of Ice " ) When the Dalek s achieved time travel , they made a version of the TARDIS , the Dalek time machine . ( TV : " The Chase " ) The Daleks built a fleet of TARDISes identical to the Doctor ' s TARDIS . ( COMIC : " Return of the Daleks " ) When Banto Zame and Sally - Anne Stubbins were running their conning operation , they used a device called a " STARDIS " which was a teleport device housed inside a portaloo . ( AUDIO : " The One Doctor " ) The Cult of Skaro utilised the Genesis Ark , a Time Lord prison ship reserved for Daleks that could carry millions at a time . ( TV : " Doomsday " ) An alternate reality UNIT , under the command of Rose Tyler , used technology taken from the Doctor ' s dying TARDIS to create a time machine to send the alternate Donna Noble back in time to correct history . ( TV : " Turn Left " ) 79B Aickman Road was a copy of TARDIS technology . ( TV : " The Lodger " ) The Eleventh Doctor later encountered a ship of identical design belonging to the Silence . ( TV : " Day of the Moon " ) Behind the scenes . Is it Tardis or TARDIS ? Is " TARDIS " somehow " more correct " than " Tardis " ? It ' s an open question , really . Here ' s what can be safely said . The acronym was introduced into written English as " Tardis " . The earliest " Doctor Who " publications — like 1960s Doctor Who annual s — consistently styled it as the ordinary word " Tardis " , capitalising the " T " and often italicising the word in deference to the fact that it was a ship name . As David J . Howe and friends once noted in a behind - the - scenes exploration of " An Unearthly Child " : This explains why World Distributors ' " Doctor Who " annuals often styled the name " Tardis " , not TARDIS , " TARDIS " or even " the Tardis " . Common sentences in early 1960s annuals ran along the lines of , " The Doctor made his way back to " Tardis " , where Ben and Polly were waiting for him . " World eventually stopped italicising " Tardis " , but they used " Tardis " throughout their stewardship of the " Doctor Who " annuals , with the form being used as late as their final edition in 1986 . Similarly , " Radio Times " listings have always treated the acronym like a regular word . Even in the 21st century , " Tardis " is the form found in dictionaries , such as the Oxford American Dictionary . Like " laser " and " sonar " , then , " Tardis " is what some linguists call an " anachronym " . Since " most " of the general public doesn ' t know that it " is " an acronym , its heritage as an acronym is viewed as anachronistic , and therefore forgotten . Different styles for different times . That said , a few generalisations can be noted . Throughout most of the classic run — at least prior to John Nathan - Turner , the preferred form was " Tardis " . Thus , in Target novelisation s , annuals , and other printed material that was actually contemporaneous with the original version of " Doctor Who " , " Tardis " is the form of choice . This began to change somewhat in the 1980s . Once " Doctor Who " became a print - only franchise in the 1990s , however , " TARDIS " became standardised by Virgin Books . BBC Wales continued with the Virgin / BBC Books style . Publications like the " Doctor Who Storybook " , New Series Adventures , Quick Reads , " The Darksmith Legacy " and the like are all fairly unanimous in their use of " TARDIS " . Nevertheless , despite the increased use of " TARDIS " in prose fiction , there still is no firm preference expressed by narratives in visual media like television episodes and comic stories . Where the word has appeared , it has done so along other words exclusively set in the uppercase . For instance , in the plaque installed on the Eleventh Doctor ' s TARDIS set , " all " the words are in uppercase , so nothing can be inferred about the " proper " way to capitalise the acronym . Equally , in " Let ' s Kill Hitler " , the word appears on a screen where all other text is in uppercase . Comic depictions have also been lettered in all uppercase , as is standard for the medium . In popular culture . In terms of general cultural references , " Tardis " is still in heavy use , as is evidenced by article titles like " XDm . 45 ACP 3 . 8 ″ Compact is the Tardis of Handguns " and BBC America ' s Where ' s the Tardis ? competition . It also seems to be BBC News ' house style to go for the sentence case version : " ' Tardis ' to tackle anti - social behaviour in Brighton " and " Tardis Tennis " , a game made by BBC Sport . Moreover , most articles supplied by BBC News about " Doctor Who " — as opposed to those written for the " Doctor Who " official website — tend to use " Tardis " throughout the body of the text , as with this coverage of the 2012 official " Doctor Who " convention . Equally , it has always been the house style of the " Radio Times " to use this form , as can be evidenced by exploring the " RT " website , as well as past " RT " clippings included on classic - era DVD s . Use on this wiki . , " TARDIS " refers to the time - travel device used by Time Lords , whereas " Tardis " means the wiki itself .